Vacuum brake — The vacuum brake is a braking system used on trains. It was first introduced in the mid 1860s and a variant, the automatic vacuum brake system became almost universal in British train equipment, and in those countries influenced by British… … Wikipedia
Vacuum tube — This article is about the electronic device. For experiments in an evacuated pipe, see free fall. For the transport system, see pneumatic tube. Modern vacuum tubes, mostly miniature style In electronics, a vacuum tube, electron tube (in North… … Wikipedia
Vacuum — This article is about empty physical space or the absence of matter. For other uses, see Vacuum (disambiguation). Free space redirects here. For other uses, see Free space (disambiguation). Pump to demonstrate vacuum In everyday usage, vacuum is… … Wikipedia
Vacuum cleaner — Cylinder vacuum cleaner for home use. French train vacuum cleaner … Wikipedia
False vacuum — In quantum field theory, a false vacuum is a metastable sector of space that appears to be a perturbative vacuum, but is unstable due to instanton effects that may tunnel to a lower energy state. This tunneling can be caused by quantum… … Wikipedia
Spontaneous symmetry breaking — Quantum field theory (Feynman diagram) … Wikipedia
QCD vacuum — The QCD vacuum is the vacuum state of quantum chromodynamics (QCD). It is an example of a non perturbative vacuum state, characterized by many non vanishing condensates such as the gluon condensate or the quark condensate. These condensates… … Wikipedia
Symmetry breaking — in physics describes a phenomenon where (infinitesimally) small fluctuations acting on a system crossing a critical point decide a system s fate, by determining which branch of a bifurcation is taken. For an outside observer unaware of the… … Wikipedia
Atmospheric vacuum breaker — An Atmospheric Vacuum Breaker (AVB) is a backflow prevention device used in plumbing to prevent backflow of non potable liquids into the drinking water system. It is usually constructed of brass and resembles a 90 degree elbow with a hood on its… … Wikipedia
Agni missile system — Infobox Weapon is missile=yes name=Agni I/Agni II/Agni III/Agni IV caption= origin= IND type=Medium Range Ballistic Missile (Agni I) Intermediate Range Ballistic Missile (Agni II, Agni III) Intercontinental Ballistic Missile (Agni IV) used by=… … Wikipedia
Drain-waste-vent system — DWV redirects here. For other uses, see Deformed wing virus. Detail of soil stack, which is connected to the sewer and vented at the top. In modern plumbing, a drain waste vent (or DWV) is part of a system that removes sewage and greywater from a … Wikipedia
