Tympanic membrane retraction commercially available devices (e.g. Otovent and Ear Popper). A ventilation tube, also known as a tympanostomy tube or a grommet, may be placed through the eardrum to equalize middle ear pressure. Although this intervention may be effective, research has not yet shown whether it provides better results than simple observation. Further weakness or perforation of the eardrum may occur. These are intended to improve Eustachian tube function. Adenoidectomy can improve middle ear function and nasal steroid sprays can reduce adenoid size but it is not known whether these treatments alter tympanic membrane retraction. Enlargement of the Eustachian tube opening in
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