A microkernel implements all drivers as user-space programs, and implements core features like IPC in the kernel itself. A monolithic kernel, however, implements the drivers as a part of the kernel...
Porcelain is made with kaolin clay. Kaolin is white clay that retains its white color when fired. It is fired at temperatures in excess of 1300 C and is more fully vitrified than stoneware. It is usually covered with a clear glaze, which allows the white body to show.
Porcelain tile is generally made by pressing porcelain clays, which results in a tile that's dense, impervious, fine grained, and smooth with a sharply formed face. Porcelain tiles usually have a much lower water absorption rate than ceramic tiles, making them more frost resistant, although not frost proof.