Drivers and barriers to achieve a circular economy of small-IT: Case study from the city of Porto.

Advances in digital electronics delivered small and portable gadgets, changing human interface with technology. Demand for new small devices of Information and Telecommunication Technology (small-IT) that have a short lifespan, like smartphones and laptops, creates flows and accumulation of electronic resources. These include precious metals that show potential for Urban Mining and Circular Economy. To find out the extent of setting up an improved recycling, reuse and repair system, data collection was conducted through surveys, bin observations and social experiments. These methods enabled us to analyse stocks and flows, identify behavioural practices and map collection infrastructure. About 80% of domestic small-IT stocks are hibernated, meaning they could be directly reused or easily repaired. Results show four barriers that keep citizens from handing in their unused small-IT: Devices are kept as back-up, they contain sentimental value, citizens are suspicious of post-collection data confidentiality issues and there is a perceived high effort to recycle. Drivers to enhance circularity are: improving e-waste infrastructure, introducing economic incentives and raising awareness on environmental impacts of hibernated stocks. A more trustworthy and legitimate management system is expected to deliver safety and confidentiality of personal data and provide the quality that fits the expectations of citizens of a proper place to dispose of their valuable items.

Baryon Acoustic Oscillations from Integrated Neutral Gas Observations: an instrument to observe the 21cm hydrogen line in the redshift range 0.13 < z < 0.45 - status update.

BINGO (BAO from Integrated Neutral Gas Observations) is a unique radio telescope designed to map the intensity of neutral hydrogen distribution at cosmological distances, making the first detection of Baryon Acoustic Oscillations (BAO) in the frequency band 980 MHz - 1260 MHz, corresponding to a redshift range 0.127 < z < 0.449. BAO is one of the most powerful probes of cosmological parameters and BINGO was designed to detect the BAO signal to a level that makes it possible to put new constraints on the equation of state of dark energy. The telescope will be built in Paraíba, Brazil and consists of two \thicksim 40m mirrors, a feedhorn array of 50 horns, and no moving parts, working as a drift-scan instrument. It will cover a 15 ^{\circ} ∘ declination strip centered at \sim \delta ∼ δ =-15 ^{\circ} ∘ , mapping \sim ∼ 5400 square degrees in the sky. The BINGO consortium is led by University of São Paulo with co-leadership at National Institute for Space Research and Campina Grande Federal University (Brazil). Telescope subsystems have already been fabricated and tested, and the dish and structure fabrication are expected to start in late 2020, as well as the road and terrain preparation.

Comparison of local and centralized biowaste management strategies - A spatially-sensitive approach for the region of Porto.

The increasing concern with greenhouse gas emissions and nutrients cycling creates a need for cost-effective, practical and environmentally sensible biowaste management strategies. Centralized systems have struggled to comply with those needs. Decentralized systems, treating waste at source, promise local nutrient circularity and increased resource sovereignty. The large-scale performance of decentralized systems remains unclear, especially concerning the local sink capacity to assimilate the treatment products. This study aimed to compare centralized and decentralized systems for the region of Porto and assess whether creating additional urban farms could reduce costs and environmental impacts. Spatial analysis was used to assess waste generation, potential compost bin locations, peri-urban and potential urban farmland available, and collection and transport requirements. The carbon footprint of different scenarios was determined using life-cycle assessment. The results show that local composting led to cost savings over centralized systems. However, this system encompassed positive carbon emissions and most districts evidenced limited sink capacity for compost application. Additional urban farms added significant sink capacity, however, their impact on cost and carbon footprint was insignificant. The carbon footprint of centralized systems was heavily dependent on factors influencing collection such as population density, and affected by the renewable content of the electricity grid. Anaerobic digestion was the most climate-friendly option in the urban center and local composting in remote and less dense districts. Municipalities may benefit from tailoring the treatment systems to specific districts, creating additional jobs while reducing cost and climate impacts overall.