A catalyst precursor suitable for the Fischer Tropsch reaction is described comprising cobalt oxide supported on a porous support wherein the porous support is a ceramic foam comprising a closed cell structure.

A catalyst precursor suitable for the Fischer Tropsch reaction is described comprising cobalt oxide supported on a porous support wherein the porous support is a ceramic foam comprising a closed cell structure.

A catalyst precursor suitable for the Fischer Tropsch reaction is described comprising cobalt oxide supported on a porous support wherein the porous support is a ceramic foam comprising a closed cell structure.

A catalyst precursor suitable for the Fischer Tropsch reaction is described comprising cobalt oxide supported on a porous support wherein the porous support is a ceramic foam comprising a closed cell structure.

The present invention is directed to a porous pre-densified CeO.sub.2 stabilized ZrO.sub.2 ceramic having a density of 50.0 to 95.0%, relative to the theoretical density of zirconia, and an open porosity of 5 to 50% as well as to ceramic having a density of 97.0 to 100.0%, relative to the theoretical density of zirconia, and wherein the grains of the ceramic have an average grain size of 50 to 1000 nm, methods for the preparation of the pre-densified and densified ceramics and their use for the manufacture of dental restorations.

The present invention is directed to a porous pre-densified CeO.sub.2 stabilized ZrO.sub.2 ceramic having a density of 50.0 to 95.0%, relative to the theoretical density of zirconia, and an open porosity of 5 to 50% as well as to ceramic having a density of 97.0 to 100.0%, relative to the theoretical density of zirconia, and wherein the grains of the ceramic have an average grain size of 50 to 1000 nm, methods for the preparation of the pre-densified and densified ceramics and their use for the manufacture of dental restorations.

A ceramic joined body includes a first aluminum oxide-based sintered body, a second aluminum oxide-based sintered body, an aluminum oxide-based joint layer located between the first aluminum oxide-based sintered body and the second aluminum oxide-based sintered body, and an aluminum oxide-based protrusion connected to the aluminum oxide-based joint layer, where the average diameter for closed pores of the aluminum oxide-based projection is 0.8 times or more and 1.5 times or less as large as the average diameter for closed pores for each of the first aluminum oxide-based sintered body and the second aluminum oxide-based sintered body.

A ceramic joined body includes a first aluminum oxide-based sintered body, a second aluminum oxide-based sintered body, an aluminum oxide-based joint layer located between the first aluminum oxide-based sintered body and the second aluminum oxide-based sintered body, and an aluminum oxide-based protrusion connected to the aluminum oxide-based joint layer, where the average diameter for closed pores of the aluminum oxide-based projection is 0.8 times or more and 1.5 times or less as large as the average diameter for closed pores for each of the first aluminum oxide-based sintered body and the second aluminum oxide-based sintered body.

The present invention relates to the use of closed-pore microspheres of expanded perlite as a filler for producing moldings for the foundry industry, to a composition for producing moldings for the foundry industry, comprising closed-pore microspheres of expanded perlite as a filler, and a binder, the binder being selected from the group consisting of water glass, phenol-formaldehyde resins, two-component systems comprising as reactants a polyisocyanate and a polyol component containing free hydroxyl groups (OH groups), and starch, and also to moldings for the foundry industry and to a process for producing a molding for the foundry industry.

The present invention relates to an agglomerate abrasive grain made up of a plurality of individual abrasive grains which are bonded into an inorganic or organic binder matrix, wherein, based on the total weight of the agglomerate abrasive grain, at least 8% by weight of the abrasive grains which are bonded into the matrix are fused alumina-based polycrystalline alumina abrasive grains with a percentage of more than 97% by weight of alpha-alumina, and wherein the polycrystalline alumina abrasive grains, in turn, are made up of a plurality of Al.sub.2O.sub.3 primary crystals with a crystal size of between 20 ?m and 100 ?m. The agglomerate abrasive grain has a closed macroporosity with a pore volume of between 5% by volume and 30% by volume, wherein the average pore diameter of the closed macropores is between 10 ?m and 100 ?m and their maximum pore diameter is in the range of approx. 120 ?m.