Checking ozone amounts by measurements of UV-irradiances

Absolute measurements of UV-irradiances in Germany and New Zealand are used to determine the total amounts of ozone. UV-irradiances measured and calculated for clear skies and for solar zenith angles less than 60 deg generally show a good accordance. The UVB-irradiances, however, show that the actual Dobson values are about 5 percent higher in Germany and about 3 percent higher in New Zealand compared to those obtained by our method. Possible reasons for these deviations are discussed

Ein Fuzzy-Control geführtes Lüftungssystem für Niedrigenergie- und Passivhäuser

Im Rahmen eines BMWT-geförderten Projekts entstand innerhalb einer Kooperation der Ritter Energie-und Umwelttechnik mit der Universität Karlsruhe (Fachbereich Bauphysik und Technischer Ausbau) eine bedarfsgeführte Fuzzy-Regelung für eine Lüftungsanlage mit Wärmerückgewinnung. Da bei Niedrigenergie-und Passivhäusern die Wärmeverluste über die Lüftung vergleichsweise hoch sind, besteht hier noch Einsparbedarf.Eine bedarfsgeführte Regelung kann die Lüftungsrate reduzieren, wenn z.B. mehrere Bewohner abwesend sind oder Fensterlüftung betrieben wird und die Luftqualität somit gut genug ist. Ausserdem wird die Lüftung reduziert, wenn die Raumluft in der Heizperiode zu trocken wird. Die sog. Fuzzy-Logik eignet sich gut für solche Regelungsaufgaben, bei denen menschliches Empfinden und Entscheiden nachgebildet werden soll. Fuzzy bedeutet eigentlich >unscharfWenn die Luft trocken ist dann wenig lüftentrockenmittelfeuchtFuzzifizierungInterferenzDefuzzifizierungColSimNormal< antritt. Gleichzeitig wird der Wohnkomfort deutlich erhöht, da Luftqualität und Feuchte stets im richtigten Bereich bleiben

What do we learn from public good games about voluntary climate action? Evidence from an artefactual field experiment

Evidence from public good game experiments holds the promise of instructive and cost-effective insights to inform environmental policy-making, for example on climate change mitigation. To fulfill the promise, such evidence needs to demonstrate generalizability to the specific policy context. This paper examines whether and under which conditions such evidence generalizes to voluntary mitigation decisions. We observe each participant in two different decision tasks: a real giving task in which contributions are used to directly reduce CO2 emissions and a public good game. Through two treatment variations, we explore two potential shifters of generalizability in a within-subjects design: the structural resemblance of contribution incentives between the tasks and the role of the subject pool, students and non-students. Our findings suggest that cooperation in public good games is linked to voluntary mitigation behavior, albeit not in a uniform way. For a standard set of parameters, behavior in both tasks is uncorrelated. Greater structural resemblance of the public goods game leads to sizable correlations, especially for student subjects

From social information to social norms::Evidence from two experiments

While preferences for conformity are commonly seen as an important driver of pro-social behaviour, only a small set of previous studies has explicitly tested the behavioural mechanisms underlying this proposition. In this paper, we report on two interconnected experimental studies that jointly provide a more thorough and robust understanding of a causal mechanism that links social information (i.e., information about the generosity of others) to donations via changing the perception of a descriptive social norm. In a modified dictator game, Experiment 1 re-investigates this mechanism adding further robustness to prior results by eliciting choices from a non-student sample and by implementing an additional treatment that controls for potential anchoring effects implied by the methods used in previous investigations. Experiment 2 adds further robustness by investigating the link between social information, (descriptive) norm perception and giving at the individual, rather than the group average, level. We find that an exogenous variation of social information influences beliefs about others&#8217; contributions (descriptive social norm) and, through this channel, actual giving. An exploratory analysis indicates that this causal relationship is differently pronounced among the two sexes. We rule out anchoring effects as a plausible confound in previous investigations. The key findings carry over to the individual level

Faddeev equation for heavy baryons in the quark-diquark picture

We describe heavy baryons as bound states of a quark and a diquark. For this purpose we derive the Faddeev equation for baryons containing a single heavy quark from a Nambu-Jona-Lasinio type of model which is appropriately extended to include also heavy quarks. The latter are treated in the heavy mass limit. The heavy baryon Faddeev equation is then solved using a static approximation for the exchanged quark.Comment: 21 pages, uses epsfig.sty, feynmp.sty; revised version to appear in Int.Journ.Mod.Phys.A (title will be changed); postscript available at http://qft3.physik.hu-berlin.de/~feldmann/pub/9601257.ps.g

Realisierung von rauschinduziertem Transport mit periodischem Antrieb

Realisierung von rauschinduziertem Transport mit periodischem Antrieb / Ch. Kettner, P. Hänggi and F. Müller. - In: Statusseminar Technische Anwendungen von Erkenntnissen der Nichtlinearen Dynamik / fachl. Konzeption: Holger Hoffschulz. - Düsseldorf : VDI, 1999. - S. 65-7

From social information to social norms: Evidence from two experiments on donation behaviour

While preferences for conformity are commonly seen as an important driver of pro-social behaviour, only a small set of previous studies has explicitly tested the behavioural mechanisms underlying this proposition. In this paper, we report on two interconnected experimental studies that jointly provide a more thorough and robust understanding of a causal mechanism that links social information (i.e., information about the generosity of others) to donations via changing the perception of a descriptive social norm. In a modified dictator game, Experiment 1 re-investigates this mechanism adding further robustness to prior results by eliciting choices from a non-student sample and by implementing an additional treatment that controls for potential anchoring effects implied by the methods used in previous investigations. Experiment 2 adds further robustness by investigating the link between social information, (descriptive) norm perception and giving at the individual, rather than the group average, level. We find that an exogenous variation of social information influences beliefs about others' contributions (descriptive social norm) and, through this channel, actual giving. An exploratory analysis indicates that this causal relationship is differently pronounced among the two sexes. We rule out anchoring effects as a plausible confound in previous investigations. The key findings carry over to the individual level