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Double dump valves have two trap-door flap plates which open and close on an alternating cycle. The top gate opens to allow collected material to drop through onto the bottom gate. The top gate then re-closes to prevent air leakage above the valve. The bottom gate then opens to allow material to pass completely through the valve.
Flap surgery is a technique essential to plastic and reconstructive surgery. A flap is defined as tissue that can be moved to another site and has its own blood supply. This is in comparison to a skin graft which does not have its own blood supply and relies on vascularization from the recipient site. [2]
A free flap is defined as a tissue mass that has been taken away from the original site to be used in tissue transplantation. [11] When a surgeon uses a free flap, the blood supply is cut and the pedicle reattached to recipient vessels, performing a microsurgical anastomosis. [12] For more information on free flaps, see also free flap.
An example of "free flap" could be a "free toe transfer" in which the great toe or the second toe is transferred to the hand to reconstruct a thumb. [ 1 ] For all "free flaps", the blood supply is reconstituted using microsurgical techniques to reconnect the artery (brings blood into the flap) and vein (allows blood to flow out of the flap).
Mitral valve repair is mainly used to treat stenosis (narrowing) or regurgitation (leakage) of the mitral valve. [citation needed] A mitral balloon valvuloplasty enlarges the valve opening to allow greater oxygenated blood flow into the left ventricle, and since severe mitral regurgitation can be a major complication, degrees of stenosis, regurgitation, and valve anatomical features are taken ...
Valve replacement surgery is the replacement of one or more of the heart valves with either an artificial heart valve or a bioprosthesis (homograft from human tissue or xenograft e.g. from pig). It is an alternative to valve repair .
Class IV valves have no more than 0.01% leakage under those conditions; this tends to require multiple graphite piston rings or a single Teflon piston ring, and lapped metal seats. Class V valves leak less than 5 × 10 −12 cubic metres, per second, per bar of pressure differential, per millimetre of port diameter, of water when tested at the ...
A hydraulic tappet, also known as a hydraulic valve lifter or hydraulic lash adjuster, is a device for maintaining zero valve clearance in an internal combustion engine. Conventional solid valve lifters require regular adjusting to maintain a small clearance between the valve and its rocker or cam follower. This space prevents the parts from ...