Tympanic membrane retraction caused by erosion of the ossicles (hearing bones). Discharge from the ear often indicates that the retraction pocket has developed into a cholesteatoma. Three factors must occur for the tympanic membrane to become retracted: When gas pressure within the middle ear is less than atmospheric pressure, the eardrum can become sucked into the middle ear space. This is caused by inadequate opening of the Eustachian tube and absorption of air from the middle ear space. People with a patulous Eustachian tube may also cause negative middle ear pressure by repeatedly sniffing to try to keep their Eustachian tube closed. The
Membrane gas separation can be economically competitive with older and more common technologies such as amine-based absorption. Currently, both membrane and amine-based absorption processes can be designed to yield a 90% CO capture rate. For carbon capture at an average 600 MW coal-fired power plant, the cost of CO capture using amine-based absorption is in the $40–100 per ton of CO range, while the cost of CO capture using current membrane technology (including current process design schemes) is about $23 per ton of CO. Additionally, running an amine-based absorption process at an average 600 MW coal-fired power plant consumes about 30% of the