Abstract: A method for producing amorphous silica includes: a pretreatment process of pulverizing vegetable material to obtain a silica source; a burning process of burning the silica source and extracting silica; and a purification process of removing carbon from burning material obtained in the burning process. The burning process includes a heating process of supplying an inert gas into a chamber and heating the silica source in the chamber in a plasma atmosphere.

Abstract: A planar heating element using for carbon micro-fibers and its manufacturing method have developed. The high-resistant carbon micro-fibers and carbon powder are efficiently coated to completely replace a conventional heating element using resistance heat of a nichrome wire. A single heating element is possibly formed to have a large width and an ultra thin heating element without temperature restriction by overcoming drawbacks of a carbon powder printed heating element serving as an initial module of the planar heating element. Thus, it is possible to produce the various convenient heating elements or heating modules using DC and AC electricity without restriction by solving problems in installation and use, for example, space restriction, thereby various convenient heating elements.

Abstract: A planar heating element using for carbon micro-fibers and its manufacturing method have developed. The high-resistant carbon micro-fibers and carbon powder are efficiently coated to completely replace a conventional heating element using resistance heat of a nichrome wire. A single heating element is possibly formed to have a large width and an ultra thin heating element without temperature restriction by overcoming drawbacks of a carbon powder printed heating element serving as an initial module of the planar heating element. Thus, it is possible to produce the various convenient heating elements or heating modules using DC and AC electricity without restriction by solving problems in installation and use, for example, space restriction, thereby various convenient heating elements.