Suchergebnisse

In this work, high-quality FASnI3 (FA, formamidinium) lead-free perovskite thin films are successfully incorporated in a flexible polyethylene terephthalate (PET) substrate to demonstrate amplified spontaneous emission (ASE) and lasing. The waveguide (WG) consists of polymethylmethacrylate(PMMA)/FASnI3 bilayer deposited on a PET substrate and is properly designed to allow single-mode propagation at the photoluminescence wavelength. This geometry optimizes the excitation of the emitting FASnI3, enhances the light−matter interaction in the semiconductor thin film, provides a preferable direction for the emitted light and allows its direct outcoupling for on-chip or fiber-optic applications. As far as the authors know, ASE and random lasing are obtained for the first time in a flexible-based WG integrating a highly efficient lead-free perovskite. The high quality of the deposited films and the optimized design of the structure result in an extremely low ASE/lasing threshold in the range of 1 µJ cm−2, which is only ten times higher than that measured in the same PMMA/FASnI3 structure deposited on a rigid substrate (Si/SiO2). More interestingly, these WGs exhibit a strong polarization anisotropy for the outcoupled ASE/lasing light with a preferable transverse electric polarization. This work is the base for the future development of ecofriendly, flexible, and efficient photonic devices. ; This project received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 862656 (project DROP-IT) and the European Research Council (ERC) via Consolidator Grant (724424, No-LIMIT) and by the Spanish MINECO through projects no. PID2020-120484RB-I00 and PID2019-107314RB-I00 (Stable).

This paper outlines how a team work approach, recently suggested in institutional economics to overcome the problem of externalities, can be used to promote better food quality. Cost sharing as "team work" is considered a novel institution to improve food quality by giving incentives to overcome the public good character of quality. We translate the approach from negative to positive externalities. Hereby: (1) We make a reference to the current state of the discussion on how food quality depends on efforts of a food industry to get a better image and discuss how much need there is to improve quality. (2) An outline of a mathematical approach of a "team work" is presented in the provision of quality as a positive externality and (3) the approach is adapted to a likely team building effort in a food industry. Finally some remarks are made how to stimulate a process of team building and the role of a government is addressed. At the core of the paper we see the argument that free riding on quality can be avoided if collective actions or team building processes occur in a community. A team is modeled as partnership of producers in which costs for quality improvement are shared.

The Canadian anti-free trade movement was a genuine 'movement' that originated locally in many different places throughout the country and was soon consolidated in a loose coalition at the national level. It was extraordinary for several reasons. First, it brought together a large number of groups that had never worked with each other before and their coalitions were strong and effective. Second, it was a movement based on class issues and was understood that way by its leaders and most of those who participated in it. Third, it democratized thinking and knowledge about economic policy, and this, in turn, meant that many groups and issues that were normally absent from a discussion of macro-economic policy, became central to the debate. Fourth, the anti-free trade movement grew in relation to the specific issues of regions and groups but the critical arguments that developed over time focused on the problems of having market mechanisms dominate both the economic and social spheres. This scrutiny and discussion of the market system itself has not been replicated in debates on any subsequent major policy issue.

Following the publication ofThe Logic of Collective Actionby Mancur Olson in 1965, the notion of free riding gained wide currency in economics. The idea of enjoying the benefits of collective action without incurring the corresponding costs seemed to shed light on a number of major issues in American society at a time when social ills of various kinds prompted policy makers to reconsider the conditions of social cohesion. Gradually, free riding became to be regarded as the standard behavior of people placed in certain circumstances rather than the exception confirming the rule that people pay for what they get.In this article, after reviewing the various meanings associated with the termfree riding(andfree rider), I follow the notion from the late 1930s to the early 1970s. I show that though it was used to tackle problems in fields as diverse as finance and labor—the study of which betrays the usual tensions between the free market and government intervention—from the mid-1960s, the notion increasingly conveyed a message about society as a whole. That an economic notion could serve such a purpose is another indication of the permeation of society by economic reasoning.