Biogas-to-biomethane upgrading: A comparative review and assessment in a life cycle perspective

The study reviews and compares the most utilised techniques to obtain high quality biomethane by upgrading biogas from anaerobic digestion of the organic fraction of municipal solid waste. Environmental and economic aspects of membrane separation, water scrubbing, chemical absorption with amine solvent, and pressure swing adsorption have been quantified in a life cycle perspective. An attributional environmental Life Cycle Assessment has been implemented with the support of a Material Flow Analysis and in combination with a complementary environmental Life Cycle Costing. The analyses are based on data largely obtained from Italian existing plants but they can be generalised to the whole European Union, as demonstrated by a companion sensitivity analysis. The comparative assessment of the results indicates all the examined options as fully sustainable, also identifying the “win-win” situations. In particular, the membrane separation technique appears to have the best performances, even though in some cases with limited differences. With reference to base case scenarios, this technique shows better results for the respiratory inorganics potential (up to 34%, i.e. up to 328 kgPM2.5eq/y), global warming potential (up to 7%, i.e. up to 344 tCO2eq/y), and non-renewable energy potential (up to 12%, i.e. up to 6400 GJprimary/y) as well as for life cycle costs (up to 3.4%, i.e. about 60 k€/y). The performances of the examined techniques appear anyway dependent on site-specific conditions (such as the injection pressure in the gas grid or the existence/amount of local economic incentives) and commercial strategies for the market of interest

An alternative management scheme for plastics from construction & demolition waste

Construction and Demolition Waste (C&DW) is a priority stream in the circular economy agenda, since it accounts for more than a third of all wastes generated in the European Union. About 1.8 Mt/y of these C&DW are plastics, whose valorisation has to overcome several obstacles: i) Current legislation recycling targets are established in terms of total recycled mass (Iodice et al., 2021), hence can be easier obtained by focusing on heavy fractions, i.e. metals and inert materials; ii) Plastics in buildings are often embedded behind walls, under floors and inside roofs: this complicates their gathering and separation (EC, 2021); iii) C&DW plastics often contain substances of concerns, allowed in the past but restricted by the current legislation (Wagner and Schlummer, 2020): the long lifetime of plastics in buildings - from about 15 years up to, sometimes, 100 years – it is thus a further technical obstacle for recycling; iv) Recycling entails high costs and needs specific policy actions to be implemented, such as landfill ban and the creation of a competitive market for secondary raw material (Pantini and Rigamonti, 2020). These constrains make collection and management schemes complex and variable from country to country. Moreover, the rare utilisation of a selective demolition as alternative to a conventional demolition further worsens the quality of recoverable materials. Please click Additional Files below to see the full abstract

Agriculture 4.0: A systematic literature review on the paradigm, technologies and benefits

Demographics will increase the demand for food and reduce the availability of labour in many countries all over the world. Moreover, scarcity of natural resources, climate change and food waste these are issues that are strongly impacting the agricultural sector and undermining sus-tainability. Digitalisation is expected to be a driving force in tackling these problems that are characterising agriculture. In particular, the adoption of digital technologies to support processes in the primary sector goes by the name of Agriculture 4.0. Although the number of contributions related to these issues is constantly growing, several areas are still unexplored or not fully addressed. This paper addresses the adoption of digital technologies and investigates the appli-cation domain of these technologies, presenting a systematic review of the literature on this subject. Moreover, this research shed light on the technologies adopted and related benefits. Hence, the research has turned its attention to the description of the main pillars, such as the categorisation of its main application domains and enabling technologies. The results of the research show that the different technologies applied in the various fields of application provide benefits both in terms of efficiency (cost reduction, farm productivity) and reduced environ-mental impact and increased sustainability

Transcranial direct current stimulation (tDCS) and language

Transcranial direct current stimulation (tDCS), a non-invasive neuromodulation technique inducing prolonged brain excitability changes and promoting cerebral plasticity, is a promising option for neurorehabilitation. Here, we review progress in research on tDCS and language functions and on the potential role of tDCS in the treatment of post-stroke aphasia. Currently available data suggest that tDCS over language-related brain areas can modulate linguistic abilities in healthy individuals and can improve language performance in patients with aphasia. Whether the results obtained in experimental conditions are functionally important for the quality of life of patients and their caregivers remains unclear. Despite the fact that important variables are yet to be determined, tDCS combined with rehabilitation techniques seems a promising therapeutic option for aphasia

Holmes' or functional tremor?

Holmes tremor is a rare kind of hyperkinetic movement disorder, clinically characterized by irregular, monolateral, high-amplitude jerks, sharing a quite similar frequency with those observed in Parkinson's disease; its generation likely relies on a combined involvement of cerebello-thalamic and nigrostriatal pathways

Transcutaneous spinal direct current stimulation

In the past 10\u2009years renewed interest has centered on non-invasive transcutaneous weak direct currents applied over the scalp to modulate cortical excitability ("brain polarization" or transcranial direct current stimulation, tDCS). Extensive literature shows that tDCS induces marked changes in cortical excitability that outlast stimulation. Aiming at developing a new, non-invasive, approach to spinal cord neuromodulation we assessed the after-effects of thoracic transcutaneous spinal DC stimulation (tsDCS) on somatosensory potentials (SEPs) evoked in healthy subjects by posterior tibial nerve (PTN) stimulation. Our findings showed that thoracic anodal tsDCS depresses the cervico-medullary PTN-SEP component (P30) without eliciting adverse effects. tsDCS also modulates post-activation H-reflex dynamics. Later works further confirmed that transcutaneous electric fields modulate spinal cord function. Subsequent studies in our laboratory showed that tsDCS modulates the flexion reflex in the human lower limb. Besides influencing the laser evoked potentials (LEPs), tsDCS increases pain tolerance in healthy subjects. Hence, though the underlying mechanisms remain speculative, tsDCS modulates activity in lemniscal, spinothalamic, and segmental motor systems. Here we review currently available experimental evidence that non-invasive spinal cord stimulation (SCS) influences spinal function in humans and argue that, by focally modulating spinal excitability, tsDCS could provide a novel therapeutic tool complementary to drugs and invasive SCS in managing various pathologic conditions, including pain

Smoke gets in your eyes: re-reading gender in the "nostalgia film"

Upon its release, American Graffiti (George Lucas, 1973) was much admired by critics and audiences alike. Yet, in subsequent years, the film became known for its supposed “flattening of history,” and celebration of patriarchal values. This article demonstrates that such a judgement owes much to Fredric Jameson’s historically contingent work on postmodernism, which argues that American Graffiti constitutes the paradigmatic nostalgia film. In contrast, using close textual analysis, I demonstrate that American Graffiti provides a more complex construction of the past, and of gender, than has hitherto been acknowledged. Far from blindly idealising the early 1960s, the film interrogates the processes through which the period and its gender relations come to be idealised. This article has consequences not only for our understanding of Lucas’ seminal film, but also for the American New Wave, and the “nostalgia” text

Transcranial direct current stimulation of the prefrontal cortex modulates working memory performance: combined behavioural and electrophysiological evidence

The present study demonstrates that tDCS can alter WM performance by modulating the underlying neural oscillations. This result can be considered an important step towards a better understanding of the mechanisms involved in tDCS-induced modulations of WM performance, which is of particular importance, given the proposal to use electrical brain stimulation for the therapeutic treatment of memory deficits in clinical settings