The durability of membrane electrode assemblies (MEAs), a key component of proton exchange membrane fuel cells (PEMFCs), is particularly affected by the frame sealing structure, which is often ...

That frame featured trees cut down between 1160 and 1170, forming one of the oldest parts of the structure ... Each beam of the intricate wooden cross-work was drawn from a different tree ...

Save guides, add subjects and pick up where you left off with your BBC account. A structure is a 3D shape made from different materials and parts. Some can be simple to build, such as a wall.

That frame featured trees cut down between 1160 and 1170, forming one of the oldest parts of the structure ... Each beam of the intricate wooden cross-work was drawn from a different tree ...