Tympanic membrane retraction tensa. Tympanic membrane retraction is fairly common and has been observed in one quarter of a population of British school children. Retraction of both eardrums is less common than having a retraction in just one ear. It is more common in children with cleft palate. Tympanic membrane retraction also occurs in adults. Attempts have been made to categorise the extent of tympanic membrane retraction though the validity of these classifications is limited. The majority of tympanic membrane retractions do not cause any symptoms. Some cause hearing loss by restricting sound-induced vibrations of the eardrum. Permanent conductive hearing loss can be
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