A reduction in working hours is being considered to tackle issues associated with ecological sustainability, social equity and enhanced life satisfaction-a socalled triple dividend. With respect to an environmental dividend, the authors analyse the time use rebound effects of reducing working time. They explore how an increase in leisure time triggers a rearrangement of time and expenditure budgets, and thus the use of resources in private households. Does it hold true that time-intensive activities replace resource-intensive consumption when people have more discretionary time at their disposal? This study on environmental issues is complemented by introducing the parameters of voluntary social engagement and individual life satisfaction as potential co-benefits of rebound effects. In order to analyse the first dividend, a mixed methods approach is adopted, enabling two models of time use rebound effects to be applied. First, semi-standardised interviews reveal that environmentally ambiguous substitutions of activities occur following a reduction in working hours. Second, estimates for Germany from national surveys on time use and expenditure show composition effects of gains in leisure time and income loss. For the latter, we estimate the marginal propensity to consume and the marginal propensity to time use. The results show that time savings due to a reduction in working time trigger relevant rebound effects in terms of resource use. However, both the qualitative and quantitative findings put the rebound effects following a reduction in working time into perspective. Time use rebound effects lead to increased voluntary social engagement and greater life satisfaction, the second and third dividends.

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This paper investigates the minimum distance for a human body in the near field of a cellular telephone base station antenna for which there is compliance with the IEEE or ICNIRP threshold values for radio frequency electromagnetic energy absorption in the human body. First, local maximum specific absorption rates (SARs), measured and averaged over volumes equivalent to 1 and to 10 g tissue within the trunk region of a physical, liquid filled shell phantom facing and irradiated by a typical GSM 900 base station antenna, were compared to corresponding calculated SAR values. The calculation used a homogeneous Visible Human body model in front of a simulated base station antenna of the same type. Both real and simulated base station antennas operated at 935 MHz. Antenna-body distances were between 1 and 65 cm. The agreement between measurements and calculations was excellent. This gave confidence in the subsequent calculated SAR values for the heterogeneous Visible Human model, for which each tissue was assigned the currently accepted values for permittivity and conductivity at 935 MHz. Calculated SAR values within the trunk of the body were found to be about double those for the homogeneous case. When the IEEE standard and the ICNIRP guidelines are both to be complied with, the local SAR averaged over 1 g tissue was found to be the determining parameter. Emitted power values from the antenna that produced the maximum SAR value over 1 g specified in the IEEE standard at the base station are less than those needed to reach the ICNIRP threshold specified for the local SAR averaged over 10 g. For the GSM base station antenna investigated here operating at 935 MHz with 40 W emitted power, the model indicates that the human body should not be closer to the antenna than 18 cm for controlled environment exposure, or about 95 cm for uncontrolled environment exposure. These safe distance limits are for SARs averaged over 1 g tissue. The corresponding safety distance limits under the ICNIRP guidelines for SAR taken over 10 g tissue are 5 cm for occupational exposure and about 75 cm for general-public exposure.

This paper argues that the contemporary growth paradigm needs to be reconsidered on a micro level of consumption and product service-systems. This becomes necessary since a dynamic link between macro strategies and micro implementation of sustainable growth is missing up to date. Therefore, mainstream sustainability strategies of efficiency and consistency are extended by sufficiency in order to integrate strategies for individual welfare within their social environment. Limits to and drivers for growth are revised and updated socially in terms of qualitative values, diminishing marginal utility or symbolic social distinction. We elaborate a definition of sustainable growth that fosters individual welfare by enhancing social enactment within the boundaries of environmental space. Shifting focus on social aspects in design fosters more sustainable production and consumption patterns while sustaining individual welfare. We derive latent indications for eco-intelligent product service-arrangements and evaluate to concepts by referring to introduced definitions and according indications. With doing so, we illustrate new pathways for the translation of sustainable growth and strategies into product service-systems.