It is realized by referring to a system formed by an ash bucket, ash storage pump, ash transporting pipe, and the air make-up pipe for compressed air.

These films can be used to make a new type of loudspeaker that works by heating and cooling the air, rather than bouncing up and down to vibrate the air directly.

Make up, perfume and skincare products used after the expiry date carry a risk of irritation and infection, Debenhams said. This is due to air and bacteria infiltrating the products.