TFIID is required for in vitro transcription of the human U6 gene by RNA polymerase III

A honing machine for finishing a trochoidal bore of a rotor housing of a rotary engine. The honing machine includes a honing head and a machine table both of which are driven by a common drive shaft separately from each other in the same direction but with an eccentrically from each other. The eccentricity is adjustable so as to make the honing head follow smoothly and finely the trochoidal inner surface. A clearance control device is also provided in the honing machine, which controls the clearance between the gears intermeshing with each other for transmitting rotation from the drive shaft to the honing head and machine table. A bias pressure control mechanism is also provided which can control the bias pressure or the honing elements of the head against the trochoidal inner periphery in response to the angular positions of the elements relative to the inner periphery. The honing macine may also include a damping device to pneumatically damp or absorb such a shock, if any, as is experienced at the contact interface between the inner periphery and the honing elements.