No abstract

No abstract

No abstract

Nanoimprint lithography (NIL) is a simple and high-resolution patterning method. Nanoimprinted structures can be fabricated not only as surface structures but also as 'buried' structures for applications such as electro-optical devices. However, a precise and nondestructive evaluation method for nanoimprinted structures has not yet been established. Synchrotron radiation ultrasmall angle X-ray scattering (SR-USAXS) is a nondestructive and high-resolution characterization method. In this study, we fabricated nanostructures on a poly(lactic acid) (PLA) film using NIL. In addition, the nanoimprinted PLA film was covered with a polystyrene thin film to fabricate a 'buried' structure. The fabricated surface and the 'buried' structure were evaluated using SR-USAXS. The scattering pattern was clearly obtained from the surface and the 'buried' structure. The size of the 'buried' structure, which was estimated from the diffraction pattern, was in good agreement with that of the surface structure. These results indicate that SR-USAXS is powerful tool for the nondestructive and precise characterization of surface and 'buried' structures.

In this study, we determined the amount of metal in one desktop personal computer (PC) as a case study of electronic and electrical waste (e-waste). Using a three-step process, we dismantled the PC. We then analyzed the metal content of each part. The circuit boards contained 0.794 g of Ag, 0.143 g of Au, 0.186 g of Pd, 91 g of Al, 187 g of Cu, and 17.8 g of Pb. In total, the PC contained 0.79 g of Ag, 0.143 g of Au, 0.19 g of Pd, 420 g of Al, 320 g of Cu, 7200 g of Fe, 77 g of Zn, 23 g of Nd, and 20 g of Pb. We also evaluated the maximum recoverable amount of metal (M-max) from waste PCs in Japan per year and determined that the M-max for Au, Ag and Pd are 1.1, 5.9, and 1.4 t per year, respectively.Key words : electronic and electrical waste, metal resources, hazardous metal, maximum recoverable amount of metal