(A or amp) The SI base unit of electric current.
Definition: Two parallel conductors, infinitely long and having negligible cross section should be placed 1 meter apart in a perfect vacuum. One ampere is the current that creates between them a force of 0.2 µN (micronewton) per meter of length.
One ampere represents a current flow of 1 coulomb of charge per second.
One ampere of current results from a potential distribution of 1 volt per ohm of resistance, or from a power production rate of 1 watt per volt of potential.
The unit is known informally as the amp, but A is its official symbol and is named for the French physicist André-Marie Ampère.
See also System International.

(ALI) The annual limit on intake refers to the body intake of radionuclides by inhalation, ingestion or through the skin in one year, which would result in a committed dose equal to the relevant dose limit.

(AMU) is equal to the mass of one-twelfth of a carbon-12 atom (6 protons + 6 neutrons (+ 6 electrons)), a 'very' little less than 1.66 x 10^-24 gram.

See also Mass Number and Atomic Mass.

(Bq) Becquerel is the system international (SI) since 1985 new unit of radioactivity. 1 becquerel is equal to 1 disintegration per second.
1 Bq = 0.027 x10^-9 Ci (Curie).
In medicine and radiation protection the SI measurement units of becquerel, gray and sievert (should) have replaced the conventional units of curie, rad and rem.

To convert:


See also Gray, Sievert, Roentgen Equivalent In Man, Radiation Absorbed Dose, Count and Becquerel Antoine Henri.

The basic unit of information.
Definition: The smallest unit of information in the storage on a computer. Eight bits are grouped together to form one byte, additional start and stop bit.
Larger units are
kilobyte (kB) = 1 000 bytes (computer storage 1024 bytes)
megabyte (MB) = 1 000 kB (computer storage 1024 kB)

See also Bit Range, Binary System, Decimation, Digitization, Sampling Rate and Picture Archiving and Communication System.

A metric unit of temperature.
Definition: One degree is 1/273.16 of the difference between the triple point of water (at exactly 0.01°C) and absolute zero.
The triple point of water is the temperature at which water can exist simultaneously in the gaseous, liquid, and solid states. Absolute zero is the temperature at which all molecular motion discontinues.
The Celsius temperature scale is named for the Swedish astronomer and physicist Anders Celsius (1701-1744), who used a similar scale.

See also Kelvin, Fahrenheit.