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Silicon is the most widely used functional material, as it is geo-abundant and atoxic. Unfortunately, its efficiency as a thermoelectric material is very poor. In this paper, we present and discuss advances of research on silicon and related materials for thermoelectric applications, mostly focusing on the comparison between the two strategies deployed to increase its performance, namely either reducing its thermal conductivity or, in polycrystalline materials, increasing its power factor. Special attention will be paid to recent results concerning silicon thin films. The enhancement of Si performances has motivated efforts to develop integrated heat microharvesters operating around room temperature, which will be reviewed also in view of their applications to power wireless sensors for the Internet of Things.

Single-crystalline silicon is well known to be a poor thermoelectric material due to its high thermal conductivity. Most excellent research has focused on ways to decrease its thermal conductivity while retaining acceptably large power factors (PFs). Less effort has been spent to enhance the PF in poly and nanocrystalline silicon, instead. Here we show that in boron-hyperdoped nanocrystalline thin films PF may be increased up to 33 mW K$^{-2}$m$^{-1}$ at 300 K when hydrogen embedded in the film during deposition is removed. The result makes nanocrystalline Si a realistic competitor of Bi$_2$Te$_3$ for low-temperature heat harvesting, also due to its greater geo-availability and lower cost.

Most works on populism framed in a discourse-analytic perspective focus on the features of populist discourse itself, contributing greatly to the understanding of the phenomenon. However, a full understanding of populism should also consider the ways in which notions of populism are constructed, negotiated, reproduced, and popularised in public discourse, as this contributes greatly to forming public opinion at large and peoples responses to populism itself. For this reason, the chapter addresses discourses about populism, with a focus on editorials dealing with Brexit in the British and Italian press. Although their position of supremacy in orienting public opinion has been partly mined by talk shows, blogs, and social media at large, opinion pieces remain one of the most important sites in which intellectuals (generally senior journalists) publicly share their views trying at the same time to influence the opinion of the readers. Based on an original framework integrating categories from critical discourse studies, argumentation theory, and the study of heteroglossia/dialogism, the analysis focuses on the ways in which editorialists define and evaluate populism and populists, the argumentative topoi they employ to support their standpoints, and whether and how they engage alternative viewpoints. In our view, all these aspects concur to expand or reduce the space of dialogue created by the text, and hence, we claim, the ability of the readers to feel included, and see their positions represented, in the broader discussion. The risk is that if no dialogue is opened at all with the people who uphold populist views, intellectual discourse will fail to involve them as interlocutors in a critical discussion, thus making them more receptive (or vulnerable) to populist propaganda.

We study the impact of electricity divestments in a stylised model where a dominant producer faces a competitive fringe with the same cost structure and is forced to sell some of its capacity. For a given demand level, the divestment which achieves the greatest reduction in prices can be several times more effective in reducing prices than a divestment of base load (or low-cost) plants. We extend this theoretical result to the case with variable electricity demand by considering a numerical example based on data from the Italian market.

We study alternative market power mitigation measures in a model where a dominant producer faces a competitive fringe with the same cost structure. We characterise the asset divestment by the dominant firm which achieves the greatest reduction in prices. This divestment entails the sale of marginal assets whose cost range encompasses the post-divestment price. A divestment of this type can be several times more effective in reducing prices than divestments of baseload (or low-cost) assets. We also establish that financial contracts (modeled as Virtual Power Plant schemes) are at best equivalent to baseload divestments in terms of consumer welfare.