Abstract: A honeycomb catalyst body includes: porous partition walls having a large number of pores and disposed to form a plurality of cells communicating between two end faces, plugged portions disposed to plug each of the cells on one of the end faces, and catalyst layers loaded in layers on an inner surface of the cells and an inner surface of the pores and containing a noble metal. Mass (Mc) of the noble metal contained in the catalyst layer loaded on the inner surface of the cells and mass (Mp) of the noble metal contained in the catalyst layer loaded on the inner surface of the pores satisfy the relation of (Mp)/(Mc)?4. The honeycomb catalyst body is excellent in purification efficiency, has low pressure loss, and is mountable even in a limited space.

Abstract: A honeycomb filter is provided comprising a honeycomb structure having a large number of through channels formed in an axial direction and partitioned by porous partition walls, each of the through channels having a first end at one end of the filter and a second end at an opposite end of the filter, wherein a first group of the through channels are plugged only at the first end, and a second group of the through channels are not plugged. A honeycomb structure is further provided having through channels with a relatively large frontal area and through channels with a relatively small frontal area, and wherein all the through channels with a relatively large frontal area are the first group, and all the through channels with a relatively small frontal area are in the second group. A honeycomb filter is also provided with a catalyst component carried on a surface of the partition walls and/or a surface of pores present in an inside of the partition walls.

Abstract: A manufacturing method of a ceramic structure of the present invention includes the steps of: forming a green body, which results from mixing and kneading materials obtained as a consequence of adding a silicon metal and an organic binder to a silicon carbide powder material; forming a formed body by molding the obtained green body; prefiring the formed body; and placing the formed body (1) after prefiring on a layer formed by a refractory firing powder (4) having a silicon metal and firing the formed body after prefiring. Adhesion of the fired body after the firing and the refractory firing powder (4) is suppressed, and evaporation of the silicon metal from the fired body is prevented.

Abstract: A silicon carbide-based porous material containing silicon carbide particles (1) as an aggregate and metallic silicon (2), wherein the average particle diameter of the silicon carbide-based porous material is at least 0.25 time the average particle diameter of the silicon carbide particles (1), or the contact angle between the silicon carbide particles (1) and the metallic silicon (2) is acute, or a large number of secondary texture particles each formed by contact of at least four silicon carbide particles (1) with one metallic silicon (2) are bonded to each other to form a porous structure. This silicon carbide-based porous material can be sintered, in its production, at a relatively low firing temperature and, therefore, can be provided at a low production cost, at a high yield and at a low product cost.

Abstract: A piezoelectric/electrostrictive film device comprises a piezoelectric/electrostrictive layer and at least a pair of electrodes formed on the piezoelectric/electrostrictive layer, wherein a perovskite piezoelectric/electrostrictive material of the piezoelectric/electrostrictive layer contains Pb, and wherein the perovskite piezoelectric/electrostrictive material contains MnO2 in an amount of 0.1 to 0.5% by weight. Specifically, the perovskite piezoelectric/electrostrictive material contains Pb(Mg⅓Nb⅔)O3-PbZrO3-PbTiO3 in which a part of Pb is substituted with Sr.

Abstract: Provided are a method for producing ceramic green sheets used for making a ceramic substrate which is reduced in cracking failure and improved in adhesion between laminated layers and is high in lamination property, high in strength and excellent in surface roughness, said method including heat-treating the ceramic powder having a specific particle size by dry grinding a ceramic powder to prepare ceramic powder having a specific average degree of aggregation and preparing a slurry using the ceramic powder so that a green density of the resulting ceramic green sheets is in a desired range, and a method for making a ceramic laminated substrate having excellent various properties by laminating the above ceramic green sheets and firing the laminate.

Abstract: A method for removing nitrogen oxides and organic chlorine compounds from a combustion waste gas, which comprises the steps of: adding ammonia (NH.sub.3) as a reducing agent to a combustion waste gas containing nitrogen oxides and organic chlorine compounds; causing the combustion waste gas added with ammonia to contact with, while keeping the temperature of the combustion waste gas within a prescribed range, with a catalyst comprising at least one selected from the group consisting of platinum (Pt), palladium (Pd), ruthenium (Ru), manganese (Mn), copper (Cu), chromium (Cr) and iron (Fe) and oxides thereof, supported on the surface of a carrier comprising at least one selected from the group consisting of titanium oxide (TiO.sub.2), silicon oxide (SiO.sub.2), aluminum oxide (Al.sub.2 O.sub.3) and zirconium oxide (ZrO.sub.2), thereby removing nitrogen oxides and organic chlorine compounds from the combustion waste gas.