V

VA

[Abbr. for Volt-ampere] - A Volt-Ampere (also volt-amp) is the basic unit of apparent electrical power. The value is derived by multiplying the voltage applied to a device (V) by the value of the current consumed by the device (A). See also Watt. 

VAC

[Abbr. for ventilation and air conditioning] - VAC systems are all those components used in air-conditioning and ventilation technology (which serves to condition guided air currents). VAC technology is distinct from process-air technology. 

vacuum

In classical physics, a vacuum is defined as space which contains no matter whatsoever. Electromagnetic waves can propagate unimpeded in a vacuum. 

vegetative propagation

The opposite of generative propagation, vegetative propagation describes asexual reproduction in biology. 

viruses

Viruses are particles or information carriers dependent for survival upon the metabolism of a host cell, since they themselves have no cytoplasm and are incapable of metabolism. Viruses are thus de facto not living organisms. 

VIS

[Abbr. for visual spectrum] - The visible electromagnetic waves - i.e light in the classic sense of the word - are termed VIS radiation. 

Vitamin D3

is a secosteroid produced in human skin from 7-dehydrocholesterol through the action of UVB radiation. 

VUV

[Abbr. for vacuum UV ] - The very short waves in the UVC range of 200 to 100 nm and under are termed vacuum UV. The name comes from the fact that this radiation only propagates in a vacuum.