Abstract: A pneumatic tire. A central circumferential main groove is disposed to extend along a tire circumferential direction, along a ground contact center line of tread of the pneumatic tire. Inboard side circumferential main grooves and inboard side lateral main grooves, which are continuous with the central circumferential main groove, are provided at an inboard side of the ground contact center line. Outboard side lateral main grooves, which are continuous with the central circumferential main groove, and outboard side slanted longitudinal main grooves, which are continuous with the outboard side lateral main grooves, are disposed at an outboard side of the ground contact center line. Thus, irregular wear of land portions is continuously suppressed and controlling stability is improved. Moreover, water at the ground contact center line, which water is difficult to drain, can be efficiently drained from the ground contact area due to less water resistance.

Abstract: In a pneumatic tire of the present invention, a pair of circumferential main grooves with a tire equatorial plane interposed therebetween, and another pair of circumferential main grooves at a tire axial direction outer side and inner side of the former pair of circumferential main grooves, are provided in a central area of a tread. A groove width center line of the circumferential main grooves at the tire axial direction outermost side and innermost side is disposed at a position 30% to 40% of a ground contact half width distanced from the tire equatorial plane. Further, outboard side slanted longitudinal main grooves, and slanted lateral main grooves having ends which open into at least one of the circumferential main grooves and other ends which open into contact ground end in the vehicle width direction, are disposed on the tread.

Abstract: A plasma treatment method and system allowing the plasma intensity to be controllably distributed perpendicularly to the inner wall and ensuring effective and uniform treatment in the case of executing plasma cleaning, plasma CVD, RIE or the like. In the plasma treatment where plasma is generated within a chamber 1 for plasma treatment, magnetic field 31 is applied perpendicularly to the inner wall of the chamber to produce plasma whose intensity is directed perpendicularly to the inner wall of the chamber or in parallel with the surface to be treated. Further, the magnetic filed 31 rendered into a revolving field 32 may be applied to rotate the plasma to accomplish a uniform and effective treatment.

Abstract: An aluminum-diffusion coated steel pipe having an aluminum-coated layer on at least the inner surface of the steel pipe to be in contact with molten metal is used as a gating pipe system in a casting mold comprising a mold body and a gating system for pouring molten metal into the mold body. This aluminum-diffusion coated steel pipe can be further subjected to a secondary heat treatment in a high-temperature oxidizing atmosphere.