A memory device includes an active area protruding from a semiconductor substrate. The light-emitting device has a light-emitting layer existing between first and second electrodes and a field effect transistor, of which the active layer is an amorphous. Further, it is possible to add understeer characteristics to a tubular beam with an oversteer tendency by minimizing the reduction in transverse rigidity and making a shear center higher. The device traps silt and other debris and can be easily removed for dumping without allowing debris to fall into the valve box. The second vectoring duct directs a third portion of core gas from the core gas duct through a second vectoring duct outlet along a second trajectory that is angularly offset to the first trajectory.