Monitoring Sound and Its Perception during the Lockdown and De-Escalation of COVID-19 Pandemic: A Spanish Study.

The lockdown measures in Spain due to the SARS-CoV-2 or COVID-19 (Coronavirus disease 2019) pandemic from 13 March to 21 June 2020 had extensive social and environmental implications. This study aims to understand how the measures of lockdown have influenced noise levels, as well as people's perception of sound quality before and after lockdown, including de-escalation. For this purpose, an online survey was carried out. Moreover, the noise linked to the Global Positioning System (GPS) position of each individual respondent was recorded aiming to correlate the noise level with the result of the survey. An average reduction of over 30 dB was observed compared with the sound pressure level before lockdown. Furthermore, it was found that the loudness parameter, together with the overall level, increased as the country started relaxing restrictions. Additionally, results showed that the perception of noise quality changed depending on the phase of de-escalation (p < 0.01), the type of property (p < 0.05), and the outside noise (p < 0.01). Moreover, noise annoyance was determined considering age (p < 0.01), gender (p < 0.05), type of property (p < 0.001), and home refurbishment (p < 0.05). It may be concluded that the most important measure to decrease noise levels is the reduction of traffic noise, through using eco-friendly public transportation or bicycles and limiting nightlife hours.

Auxiliary energy-assisted biodiesel production data from solid food waste oil.

A number of samples from solid food waste oil (SFWO) from different restaurants have been collected. Data regarding fatty acid profile, acid value, water content and kinematic viscosity were used for characterization purposes. Response surface methodology data has been used to carry out conventional transesterification optimization. The quality of the final product has been checked following the European biodiesel standard EN14214. To compare conventional and ultrasound-assisted transesterification results, energy consumption and reaction time data have been gathered. More information and result interpretation may be found in "Optimization of solid food waste oil biodiesel by ultrasound assisted transesterification" [1].