Abstract: An ion transport optical system includes N rod electrodes forming an N-pole arrangement externally tangent to a circle of diameter A1 at an ion-entrance end, where N is an even number not smaller than six. Four electrodes form a quadrupole arrangement externally tangent to a circle of diameter A2 at an ion-exit end, where A2<A1. At least two of them are arranged obliquely to the central axis of the N-pole or quadrupole arrangement. At least four of the N electrodes are shaped such that the cross-sectional radius of their arc-shaped portion facing the central axis at the ion-exit end is smaller than that at the ion-entrance end. A voltage generator applies a DC voltage to the four electrodes and another DC voltage, which differs from the first one, to the N?4 remaining electrodes, in addition to RF voltages of opposite phases alternately applied to the N electrodes.

Abstract: A pair of middle cowls is arranged at positions rightward and leftward of a vehicle component located at a position forward of an engine. Part of the right middle cowl is arranged at a position further forward than an air cleaner case. A space in the air cleaner case is divided by a filter element into a first space positioned at a position further downstream than the filter element and a second space positioned at a position further upstream than the filter element. The second space is smaller than the first space. The second space and a third space inward of the right middle cowl communicate with each other by a communicating portion. The second space, at least part of the third space, and an internal space of the communicating portion constitute a dirty side chamber of an air cleaner.

Abstract: A pair of middle cowls is arranged at positions rightward and leftward of a vehicle component located at a position forward of an engine. Part of the right middle cowl is arranged at a position further forward than an air cleaner case. A space in the air cleaner case is divided by a filter element into a first space positioned at a position further downstream than the filter element and a second space positioned at a position further upstream than the filter element. The second space is smaller than the first space. The second space and a third space inward of the right middle cowl communicate with each other by a communicating portion. The second space, at least part of the third space, and an internal space of the communicating portion constitute a dirty side chamber of an air cleaner.

Abstract: A method and an apparatus for detecting a flaw on threads of a male screw, which comprises: fully applying a light from a light source onto tops, roots and flanks of threads of a male screw while rotating the male screw around the axis thereof; continuously measuring, by means of a photoelectric converter, electric signal values corresponding to variations in brightness of the male screw in the axial direction thereof during one turn of the male screw around the axis thereof; moving-averaging the thus measured electric signal values corresponding to the variations in brightness of the male screw in the axial direction thereof; determining electric signal values corresponding to variations in brightness of the male screw in the circumferential direction thereof, on the basis of the thus moving-averaged electric signal values corresponding to the variations in brightness of the male screw in the axial direction thereof; obtaining a mean square value of the thus determined electric signal values corresponding to