ABSTRACT
Each year, a large amount of waste paper (WP) is generated in Japan, and due to the change in lifestyle with the COVID-19 pandemic, the WP collection and recycling system in Japan faces new challenges. Although the government of Japan has installed WP collection systems, the efficiency of these traditional WP collection systems is too low, and this causes inconvenience to the governments, residents, and other stakeholders. On the other hand, some recycling companies in Japan are trying to establish a nontraditional WP collection system by setting their own WP collection stations in cooperative supermarkets. Yet, the efficiency of this new system has not been clarified. This research aims to investigate the current status, operational characteristics, and the role of recycling companies’ WP collection stations in the Japanese WP collection system. By performing trade area analysis and stepwise OLS regression, this research will evaluate WP collection stations’ efficiency. Moreover, this research will also discuss how the new WP collection system improves WP collection efficiency and residents’ convenience. The results show that WP collection stations efficiency is particularly high in large supermarkets with many parking spaces and long business hours, as well as in areas with many families with children. Recycling companies’ WP collection system could create a system, which can satisfy resident, government, and recycling company interests at the same time.
ABSTRACT
It is known that silver has microbicidal qualities; even at a low concentration, silver is active against many kinds of bacteria. Silver nanoparticles (AgNPs) have been extensively studied for a wide range of applications. Alternately, the toxicity of silver to human cells is considerably lower than that to bacteria. Recent studies have shown that AgNPs also have antiviral activity. We found that large amounts of hydroxyl radicals-highly reactive molecular species-are generated when AgNPs are irradiated with ultraviolet (UV) radiation with a wavelength of 365 nm, classified as ultraviolet A (UVA). In this study, we used electron spin resonance direct detection to confirm that UV irradiation of AgNPs produced rapid generation of hydroxyl radicals. As hydroxyl radicals are known to degrade bacteria, viruses, and some chemicals, the enhancement of the microbicidal activity of AgNPs by UV radiation could be valuable for the protection of healthcare workers and the prevention of the spread of infectious diseases.