Search results
Results from the WOW.Com Content Network
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Pages for logged out editors learn more
External vacuum sealers involve a bag being attached to the vacuum-sealing machine externally. The machine will remove the air and seal the bag, which is all done outside the machine. A heat sealer is often used to seal the pack. Typically these units use a dry piston vacuum pump which is often considered a "maintenance-free" pump.
Materials for use in vacuum are materials that show very low rates of outgassing in vacuum and, where applicable, are tolerant to bake-out temperatures. The requirements grow increasingly stringent with the desired degree of vacuum to be achieved in the vacuum chamber. The materials can produce gas by several mechanisms.
A diagram of a vacuum aspiration abortion procedure at 8 weeks gestation. Figure I: The vagina is held opened by a speculum [4] in order for a tube (called a vacurette [5]), which is attached [6] to a suction pump, to be inserted through the patient's cervix.
A diagram of a vacuum aspiration abortion procedure at 8 weeks gestation. The vagina is held opened by a speculum [4] in order for a tube (called a vacurette [5]) which is attached [6] to a suction pump to be inserted through the patient's cervix.
Later thermionic vacuum tubes, mostly miniature style, some with top cap connections for higher voltages. A vacuum tube, electron tube, [1] [2] [3] thermionic valve (British usage), or tube (North America) [4] is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.