The invention relates to a blank for producing a dental molded part such as an inlay, onlay, crown or bridge, and to a method for producing the blank. To be able to machine a dental molded part, in particular one having thin wall thicknesses, from the blank without difficulty, the blank is designed to consist of a glass ceramic having a density of between 30 and 60% of theoretical density, and of glass-ceramic powder particles with a particle size distribution d.sub.90≦80 μm, lithium silicate crystals being present in an amount of 10 to 90% by volume.

A wavelength converter is provided with a light-transmitting substrate and with a thin film that is formed on a surface of the light-transmitting substrate and that contains a phosphor. A sintered body that constitutes the light-transmitting substrate has an average particle size of 5-40 μm. The light-transmitting substrate contains at least 10-500 ppm by mass of MgO. The principal component of the phosphor is an α-sialon that is indicated by the general formula (Ca.sub.α,Eu.sub.β) (Si,Al).sub.12(O,N).sub.16 (provided that 1.5<α+β<2.2, 0<β<0.2, and O/N≦0.04).

A wavelength converter is provided with a light-transmitting substrate and with a thin film that is formed on a surface of the light-transmitting substrate and that contains a phosphor. A sintered body that constitutes the light-transmitting substrate has an average particle size of 5-40 μm. The light-transmitting substrate contains at least 10-500 ppm by mass of MgO. The principal component of the phosphor is an α-sialon that is indicated by the general formula (Ca.sub.α,Eu.sub.β) (Si,Al).sub.12(O,N).sub.16 (provided that 1.5<α+β<2.2, 0<β<0.2, and O/N≦0.04).

Provided is a glass composition that exhibits greater Faraday effect than ever before. A glass composition contains 48% or more of Tb.sub.2O.sub.3 (exclusive of 48%) in % by mole.

Provided is a glass composition that exhibits greater Faraday effect than ever before. A glass composition contains 48% or more of Tb.sub.2O.sub.3 (exclusive of 48%) in % by mole.

A method of forming an opaque quartz glass component is provided. The method includes (a) providing a starting preform made of quartz glass; (b) heating at least a portion of the starting preform to a predetermined temperature at which the quartz glass of the starting preform has a viscosity in a range of 10E2 to 10E12 poise; and (c) deforming at least a portion of the heated preform at the predetermined temperature to change a shape and/or dimension(s) of the heated perform in order to form the opaque quartz glass component. The starting preform and the heated preform have respective densities of at least 2.15 g/cm.sup.3 and at least 2.10 g/cm.sup.3. The starting perform and the opaque quartz glass component have respective direct spectral transmissions of approximately 0.1-1% and 0.2-3% in the wavelength range of λ=190 nm to λ=4990 nm at a wall thickness of 3 mm and a diffuse reflectance of at least 60% in a wavelength range of λ=190 nm to λ=2500 nm.

One aspect relates to a process for the preparation of a quartz glass body. The process includes providing a silicon dioxide granulate from a pyrogenically produced silicon dioxide powder, making a glass melt out of silicon dioxide granulate, and making a quartz glass body out of at least part of the glass melt. The size of the quartz glass body is reduced to obtain a quartz glass grain. The quartz glass body is processed to make a preform and an opaque quartz glass body is made from the preform. One aspect further relates to an opaque quartz glass body which is obtainable by this process. One aspect further relates to a reactor and an arrangement, which are each obtainable by further processing of the opaque quartz glass body.

Provided is a process for producing a wavelength conversion member which can suppress the reaction between inorganic nanophosphor particles and glass to suppress the deterioration of the inorganic nanophosphor particles, and the wavelength conversion member. The process for producing a wavelength conversion member includes the steps of: preparing inorganic nanophosphor particles 1 with an organic protective film formed on respective surfaces thereof; and mixing the inorganic nanophosphor particles 1 with glass powder and firing a resultant mixture in a temperature range where the organic protective films remain as retained films 3.

Provided is a process for producing a wavelength conversion member which can suppress the reaction between inorganic nanophosphor particles and glass to suppress the deterioration of the inorganic nanophosphor particles, and the wavelength conversion member. The process for producing a wavelength conversion member includes the steps of: preparing inorganic nanophosphor particles 1 with an organic protective film formed on respective surfaces thereof; and mixing the inorganic nanophosphor particles 1 with glass powder and firing a resultant mixture in a temperature range where the organic protective films remain as retained films 3.

Consolidated porous media samples and methods for their manufacture are described herein. An assembly has an outer tube having a first softening temperature and a sintered glass construct formed from plurality of beads of multiple sizes. The sintered glass construct defines pores and at least one fracture or channel. The assembly is formed by suspending at least one sheet or wire of dissolvable material in the outer tube, packing beads of different sizes around the sheet or wire, sintering the beads with the sheet or wire located therein at a temperature below the softening temperature of the tube, and dissolving the sheet or wire to generate a sintered construct defining at least one fracture or channel.