Spatial Distribution and Quality of Urban Public Spaces in the Attica Region (Greece) during the COVID-19 Pandemic: A Survey-Based Analysis

This study investigates the spatial distribution and quality of urban public spaces in the Attica region during the COVID-19 pandemic. A questionnaire survey was conducted to gather data on the availability, accessibility, and quality of open urban public spaces. The findings indicate that, although several respondents reported the presence of outdoor public spaces in their respective areas, these spaces often did not meet the desired quality standards. Notably, a clear preference was expressed for open public spaces located within a convenient walking distance, typically within a 15-min walk. Quality assessments varied across different sectors of Attica, with the central Athens and central Piraeus sectors receiving lower ratings in terms of availability, quality, and safety. Compared to the rest of Attica, the residential suburbs of Athens’s Northern Sector appear to have more accessible, safe, and well-maintained public areas. The research underscores the critical importance of quality public spaces, particularly during times of crisis. This study emphasizes the need for a re-evaluation of urban planning strategies to ensure that public spaces remain functional and accessible to citizens

Waste Classification of Spent Refractory Materials to Achieve Sustainable Development Goals Exploiting Multiple Criteria Decision Aiding Approach

The recycling of used refractory materials in the heavy industry constitutes one of the significant environmental problems in the industry related to environmental and financial issues. This study proposes a multicriteria methodological frame to characterize the refractory material waste and identify the recycling capabilities. Considering the chemical and physical analysis of the refractory material wastes, the proposed methodological frame progresses into a two-phase procedure. The first phase includes an on/off approach that allows discretizing the refractory material wastes to compatible or not compatible as far as their recycling prospects. Then, an additive value model is utilized, including (a) the marginal value functions used for every criterion related to critical environmental factors, and (b) the weight vector reflecting the relative importance of the criteria used. A group of experts concerning the environment and the refractory materials was employed to estimate the additive value model. The assessment of the marginal value function is achieved using the module of the Multicriteria Interactive Intelligence Decision Aiding System (MIIDAS), which is based on a modification of the mid-value split point technique incorporating focused dialogues, artificial intelligence, and visual techniques. The weight vector was assessed using the weight assessment through prioritization method (WAP), which concludes with the estimation of the weights based on the criteria ranking and the pairwise expression of the strength of preferences for the consecutive criteria according to their ranking. The outcome of this approach is to introduce an environmental appropriateness index for refractory materials based on their chemical composition and the judgement of an expert group. The main findings of this research may be useful for engineers, decision-makers, and scientists in the field of circular economy and waste management