主权项 |
1. An apparatus comprising:
a block of a converter having a plurality of channels defining interior walls, which define a cellular pattern in a cross-sectional view of said block, whereby the pattern comprises regular sub-patterns consisting of at least one central channel and a plurality of surrounding channels, each central channel, which is proximate an interior of the block, is surrounded by five or more surrounding channels, the interior walls having a varying thickness of separation along a perimeter of each central channel. |