the hole

To achieve these improvements, the research team focused on understanding the efficiency and stability losses induced by the hole transport layer which plays an important role in the solar cell performance.

But as they were digging the hole to bury the wood, the scientists discovered an old log.

These pores have specific sizes, shapes and other chemical attributes wherein only certain compounds whose characteristics match the 'hole' can fit.

This is part of the Vala Umgodi, or "Close the Hole", operation to curb illegal mining.

In an interview with the BBC in July, she admitted retirement was "harder than I expected it to be" and "nothing can fill the hole of ski racing".