0 a small hole, or a number or line of small holes, made in a sheet of paper etc -- lỗ răng cưa
1 the act of perforating or being perforated. -- sự đục thủng
Three suction perforations were located on the upper surface 450 mm from the leading edge.
When excising this region, it is important to remember that extensive resection can lead to perforation of the heart wall.
As it progresses downstream of the perforation the vortex diffuses and its core migrates away from the surface.
There were no deaths, pulmonary artery perforations or acute aneurysm formations.
Comparisons are now made between the predictions and measurements for isolated holes and single rows of super-scale perforations.
However, 30% of stents occlude or migrate, and they can also cause bleeding or perforation.
There is a need for a theory to determine the optimal combination of the perforation geometry and the bias flow.
Three 1-cm2 perforations were made on each side of the litterbags to allow macro-fauna to enter.
