Suchergebnisse

To achieve the climate goals of the German government and the resulting reduction in CO$_{2}$ emissions, it is important to develop efficient energy converters. Here, an electrochemical energy conversion using direct methanol fuel cells (DMFCs) offers significant potential, since these cells' ease of use and their low exhaust emissions are significant advantages over commercial diesel engines. However, to further increase the competitiveness of DMFCs, there must be a significant increase in stack efficiency and long-term stability. The present study deals with operational management strategies for DMFC systems, and their development focus is on maximizing the efficiency of the stack and increasing the long term stability of the system. In the context of a long-term stability increase, the effects of sensor faults and cell aging on critical operating ranges are considered, since they cause a deterioration of the maximum stack efficiency and an increased aging of DMFCs. To develop a basic operational management concept, a DMFC overall model is created that takes characteristic properties into account. Based on this, a model-based predictive control is designed, that has the basic stability criteria of operating areas and the provision of the required output power. The concept of maximum stack efficiency is realized through a static economic optimization, which uses the characteristic models generated in the work. In practice, the methods developed demonstrate that a significant increase in stack efficienc yby 7 percentage points is possible, and that the required stability criteria are met at each time of operation. To extend the model in terms of long-term stability and associated aging phenomena, the measurement data of a 25,000-hour DMFC experiment is analyzed to generate an age dependent model. The initial model of a DMFC is retained in this context, and it is expanded by the characteristic aspect of the degree of aging. By means of this age-dependent model, a simulative evaluation of the aging and possible ...

Aim: The purpose of the study is to present adolescents' perceptions of smokers and non-smokers among 1015 Swiss adolescents. Method: The analyses are based on data from Tobacco Monitoring Switzerland, which is a survey of tobacco consumption in Switzerland. To measure the perceptions of smokers and non-smokers, respondents were asked to attribute a series of adjectives to each group. It was also recorded when respondents mentioned that "there is no difference between smokers and non-smokers." Results: Results show that regardless of whether the adolescents smoked or did not smoke – with the exception of more sociable – the image of smokers was more negative than the image of non-smokers. Findings also indicated that regular smokers in particular often stated that there are no differences between both groups. Conclusions: Overall, the image of smokers is more negative than the image of non-smokers, with the exception of the attribute more sociable. This perception of smokers could be important for prevention measures in new contexts (e. g., school transitions), where smoking could be a means of establishing new social ties.

This study constitutes the first psychometric examination of the German-language version of the Compensatory Health Belief (CHB) scale to assess the belief that unhealthy behavior can be compensated for by engaging in healthy behavior. Data from four different Swiss samples of 1,571 adolescents/students (age range 15 – 55 years), collected between 2007 and 2009, were used. Confirmatory factor analysis did not support either the hypothesized 4-factor structure or a second-order factor structure with a latent overall variable for the German-language CHB scale. These results support the inconsistent patterns of CHBs found across European cultures. Thus, the development of behavior-specific scales might be of advantage. Further recommendations for an improvement of the measurement of compensatory health beliefs are discussed.

Landschaften bilden die räumliche Grundlage des Lebens und sind für uns Menschen gleichzeitig Wohn­, Arbeits­, Erholungs­, Kultur­ und Wirtschaftsraum. Die Qualität von Landschaften lässt sich nur fördern, wenn ihr Nutzen benannt und deutlich gemacht wird. Dies geschieht aktuell in raumrelevanten Projekten viel zu selten. Mit dem partizipativen Ansatz der «Landschaftsleistungen» lassen sich Funktionen von Landschaften bezeichnen, die den Individuen und der Gesellschaft einen direkten wirtschaftlichen, sozialen und/oder ökologischen Nutzen bringen. Die Landschaftsleistungen bieten somit eine wichtige Grundlage für den Dialog bei der Gestaltung von Landschaf­ten. Das Factsheet leistet damit einen Beitrag zur Umsetzung des 2020 verabschiedeten Landschaftskonzeptes Schweiz und anderer politisch­gesellschaftlicher Vorhaben. ; Keller R, Clivaz M, Backhaus N, Reynard E, Lehmann P, Schüpbach U (2022) Leistungen von Landschaften fassbar machen. Swiss Academies Factsheets 17 (1)

Landscapes provide the physical foundation for life and simultaneously give us space for living, working, recreation, culture, and commerce. The added quality of landscapes for humans can only be fostered when landscape benefits are identified and made explicit. At present, this occurs far too rarely in spatially relevant projects. The participatory approach of 'landscape services' can be used to identify the functions of landscapes that contribute direct economic, social, and/or ecological benefits to individuals and wider society. In this way, landscape services provide an important basis for dialogue in the design of landscapes. The present factsheet supports implementation of the Swiss Landscape Concept adopted in 2020, in addition to other political-societal initiatives. ; Keller R, Clivaz M, Backhaus N, Reynard E, Lehmann P, Schüpbach U (2022) Making Landscape Services Tangible. Swiss Academies Factsheets 17 (1)

I paesaggi costituiscono il sistema territoriale in cui si sviluppano ecosistemi e spazi per abitare, lavorare, socializzare e stabilire relazioni culturali ed economiche. Per promuovere la loro qualità è necessario sottolinearne ed esplicitarne i benefici. Nei progetti di rilevanza territoriale questo avviene ancora troppo raramente. L'approccio partecipativo focalizzato sulle prestazioni del paesaggio consente di definire le funzioni che offrono benefici economici, sociali e/o ecologici per gli individui e la società. Queste prestazioni rappresentano quindi una base importante per il dialogo nell'ambito della gestione del paesaggio. In quest'ottica, la presente scheda informativa contribuisce alla messa in atto della Concezione «Paesaggio svizzero», adottata nel 2020, e di altre iniziative politico-sociali. ; Keller R, Clivaz M, Backhaus N, Reynard E, Lehmann P, Schüpbach U (2022) Rendere tangibili le prestazioni del paesaggio. Swiss Academies Factsheets 17 (1)