A diacritic chording system uses a single standard keyboard layout to generate diacritical characters used, for example, by Latin-based languages or languages based on a Roman character set, providing a universal keyboard The key combination required to select a diacritic is consistent, independent of the language the user is typing. The brush roller includes a shaft and a brush. The stainless steel insert includes a base portion that seats against an O-ring in a floor of the outboard cavity, and a stem portion within the O-ring that extends axially through the neck portion of the pressure port and into its inboard cavity. The densifier compacts the biomass into a multitude of compressed biomass pieces. The composite nanoparticles obtained in step i) are mixed with the thermoplastic polycarbonate matrix in the molten state to obtain the transparent polymer material.