An installation for melting a composition of raw materials, suitable for obtaining glass wool, textile glass yarns and/or flat glass, includes a melting chamber equipped with at least one submerged burner, wherein the melting chamber is defined by side walls made of refractory material and a bare metal bottom traversed by a network of pipes adapted for the circulation of a cooling fluid.

The invention discloses porous, bioactive glass and glass ceramic morsels or pellets to be used as tissue graft substitute materials and processes for obtaining the same wherein the bioactive glass and glass ceramic morsels or pellets are made up of natural agents like phosphate, calcium, sodium and other elements which are not alien to the human or animal body. The said preparation process encompasses various steps like quenching sintering, foaming, and sol-gel casting which render the glass morsels or pellets unique bioactivity and enhanced porosity which may facilitate tissue repair and augmentation during tissue graft replacement.

The invention discloses porous, bioactive glass and glass ceramic morsels or pellets to be used as tissue graft substitute materials and processes for obtaining the same wherein the bioactive glass and glass ceramic morsels or pellets are made up of natural agents like phosphate, calcium, sodium and other elements which are not alien to the human or animal body. The said preparation process encompasses various steps like quenching sintering, foaming, and sol-gel casting which render the glass morsels or pellets unique bioactivity and enhanced porosity which may facilitate tissue repair and augmentation during tissue graft replacement.

A glass fiber according to the present invention is suitable for preventing filament breakage and suitable for being stably produced for a long term, and has a β-OH value of 0.02 mm.sup.−1 or more and less than 0.55 mm.sup.−1. The preferred content of SO.sub.3 is more than 0 ppm and 70 ppm or less on a mass basis. The glass fiber is preferably substantially free of As and Sb. SO.sub.3 can be supplied to a glass raw material as, for example, a sulfuric acid salt of an alkali metal or an alkaline-earth metal.

A glass fiber according to the present invention is suitable for preventing filament breakage and suitable for being stably produced for a long term, and has a ?-OH value of 0.02 mm.sup.?1 or more and less than 0.55 mm.sup.?1. The preferred content of SO.sub.3 is more than 0 ppm and 70 ppm or less on a mass basis. The glass fiber is preferably substantially free of As and Sb. SO.sub.3 can be supplied to a glass raw material as, for example, a sulfuric acid salt of an alkali metal or an alkaline-earth metal.

The present invention provides a nozzle plate and the use of the nozzle plate for producing filaments, preferably silica gel fibers.

Sol-gel methods, apparatus and compositions for cladding optical fiber cores provide optical fibers, including single crystal optical fiber cores with polycrystalline cladding, having improved performance in a variety of applications, such as fiber lasers.

Disclosed are apparatuses and methods for growing thin crystal fibers via optical heating. The apparatuses may include and the methods may employ a source of optical energy for heating a source material to form a molten zone of melted source material, an upper fiber guide for pulling a growing crystal fiber along a defined translational axis away from the molten zone, and a lower feed guide for pushing additional source material along a defined translational axis towards the molten zone. For certain such apparatuses and the methods that employ them, the lower feed guide's translational axis and upper fiber guide's translational axis are substantially aligned vertically and axially so as to horizontally locate the source material in the path of optical energy emitted from the optical energy source, in some cases to within a horizontal tolerance of about 5 m.

The present invention provides a nozzle plate and the use of the nozzle plate for producing filaments, preferably silica gel fibers.

An installation for melting a composition of raw materials, suitable for obtaining glass wool, textile glass yarns and/or flat glass, includes a melting chamber equipped with at least one submerged burner, wherein the melting chamber is defined by side walls made of refractory material and a bare metal bottom traversed by a network of pipes adapted for the circulation of a cooling fluid.