A mixture of biomass and vitrifiable raw material for introducing into a fuel combustion furnace for the melting of a vitrifiable inorganic material, such as glass or rock or a silicate, includes an oleaginous biomass, the use of which reduces the damage to the equipment for metering and transporting the vitrifiable raw material.

A mixture of biomass and vitrifiable raw material for introducing into a fuel combustion furnace for the melting of a vitrifiable inorganic material, such as glass or rock or a silicate, includes an oleaginous biomass, the use of which reduces the damage to the equipment for metering and transporting the vitrifiable raw material.

Methods and systems for producing a hollow-core optical fiber preform and/or components thereof are described herein. In some embodiments, the method may include providing a precursor material, extruding the precursor material through a die assembly to a shaped body, and forming a hollow-core optical fiber preform or a component thereof from the shaped body. In some embodiments, providing the precursor material may include one of: heating the precursor material such that a viscosity of the precursor material reaches about 10.sup.3 to about 10.sup.7 poise, or forming a paste comprising a glass powder and a binder. In some embodiments, the hollow-core optical fiber preform may include an outer tube. In some embodiments, the hollow-core optical fiber preform may further include one of an inner tube coupled to the outer tube, or a spiral coupled to the outer tube.

Methods and systems for producing a hollow-core optical fiber preform and/or components thereof are described herein. In some embodiments, the method may include providing a precursor material, extruding the precursor material through a die assembly to a shaped body, and forming a hollow-core optical fiber preform or a component thereof from the shaped body. In some embodiments, providing the precursor material may include one of: heating the precursor material such that a viscosity of the precursor material reaches about 10.sup.3 to about 10.sup.7 poise, or forming a paste comprising a glass powder and a binder. In some embodiments, the hollow-core optical fiber preform may include an outer tube. In some embodiments, the hollow-core optical fiber preform may further include one of an inner tube coupled to the outer tube, or a spiral coupled to the outer tube.