Crowding in or crowding out? The effect of imported environmentally sound technologies on indigenous green innovation.

International trade is considered an important conduit for disseminating environmentally sound technologies (ESTs), but there is limited evidence of how trade in ESTs affects domestic firms' green innovation, particularly for importers. To close this knowledge gap, we first develop a basic model to conceptually examine how imported ESTs impact enterprises' performance in green innovation. Then, by creating a distinct combined database of firm-level trade and patent data from 2000 to 2016, we give empirical evidence. Our empirical results demonstrate a significant crowding-out effect of imported ESTs on green innovation, whereas technological proximity, learning capacity, and government subsidies can help to lessen this adverse effect. Furthermore, imported ESTs of peer firms in the same industry or imported ESTs of downstream industries have beneficial spillover effects on a focal firm's green innovation. Our study offers fresh perspectives on the current status and potential future of liberalizing trade in ESTs, as well as on the sources of green innovation.

Study Effect of nAg Particle Size on the Properties and Antibacterial Characteristics of Polysulfone Membranes.

Polysulfone ultrafiltration membranes were fabricated using various sizes (20, 40, and 90-210 nm) of silver nanoparticles (nAg) blended in a dope solution. To characterize the performance and properties of the prepared membranes, scanning electron microscopy (SEM), water contact angle, protein separation, water flux, and antibacterial tests were conducted. The characterization results revealed that when nAg particles (20 nm) were blended into the base polymer PSF, the PSF/nAg blended membrane had the lowest contact angle (58.5°) and surface energy (110.7 mN/m). When experimenting with ultrafiltration using protein solutions, bare PSF and PSF/nAg-20 blended membranes gave similar values of protein rejection: 93% of bovine serum albumin (BSA) and 70% of lysozyme rejection. Furthermore, SEM studies showed that the surface pore size was reduced by adding 20 nm nAg particles in the casting solution. Most importantly, the introduction of 40 nm nAg particles reduced the growth of bacterial colonies on the membrane surface by up to 72%. These findings revealed that nAg particles are expected to be a potential modifier for the fabrication of an ultrafiltration membrane.