Abstract: A ceramic honeycomb structure having a large number of flow paths partitioned by porous cell walls, the cell walls comprising at least main crystals of aluminum titanate, in which MgO and SiO2 are dissolved to form a solid solution, and glass phases, the glass phases containing 40-80% by mass of SiO2 and 1-20% by mass of MgO, the average size of the glass phases being 30 ?m or less in a cross section of the cell walls, and the area ratio of the glass phases to the total area of the main crystals of aluminum titanate and the glass phases being 2-12% in a cross section of the cell walls, and its production method.

Abstract: A process and device enabling accurate mass flow control is described. A mass flow controller can be re-specified corresponding to multiple types of actual process gases and multiple flow rate ranges, even after the mass flow controller has been shipped. Calibration gas data is derived using actual flow rate versus a flow rate setting signal to generate calibration gas data. Actual gas data is derived by measuring actual flow rate versus a flow rate setting signal for each actual gas and saving. Subsequently, prior to operating the mass flow rate control device, the characteristic data for an actual and the calibration gas characteristic data is recalled. The calibration gas characteristic data is then converted to controlled flow rate correction data based on the actual gas characteristic data that is saved to the control unit and the actual gas flow rate is corrected based on this controlled flow rate correction data.

Abstract: An apparatus for cutting a sheet stack is provided. The sheet stack is composed of a plurality of sheets. The apparatus includes a cutting blade having a plate form and having a cutting edge at one side extending along a cutting width direction. The cutting blade has at the one side: a plurality of projecting blade portions having ridge lines forming edge lines capable of thrusting and sawing cutting, the projecting blade portions projecting in a cutting direction; and a straight bottom portion between adjacent projecting blade portions. Cutting of the sheet stack is performed by applying a load to the cutting blade in the cutting direction, and by reciprocating the cutting blade along the cutting width direction.