a cone of coherent radiation in the radio or microwave part of the electromagnetic
spectrum. It is similar to the Cherenkov radiation. It is named after Gurgen
Askaryan, a Soviet-Armenian physicist who postulated it in 1962.
The radiation was first observed experimentally in 2000, 38 years after its theoretical prediction. So far the effect has been observed in silica sand, rock salt, ice,
and Earth’s atmosphere.
The effect is of primary interest in using bulk matter to detect ultra-high energy
neutrinos. The Antarctic Impulse Transient Antenna (ANITA) experiment uses antennas attached to a balloon flying over Antarctica to detect the Askaryan radiation produced as cosmic neutrinos travel through the ice. Several experiments have also used
the Moon as a neutrino detector based on detection of the Askaryan radiation.
Blocking
Adhesion between touching layers of plastic film (also called static blocking when
it occurs at room temperature). Adhesion of adjacent layers of plastic film after
conditioning at warm temperatures (also qualified as "thermal blocking").
Breaking Factor
The tensile strength per unit width of films or composites of specified uniform
weight per unit area.
Brewer-Dobson circulation
This is a model of atmospheric circulation, proposed by Alan Brewer in 1949 and
Gordon Dobson in 1956, which attempts to explain why tropical air has less ozone
than polar air, even though the tropical stratosphere is where most atmospheric
ozone is produced. It is a simple circulation model that posits the existence of a
slow current in the winter hemisphere which redistributes air from the tropics to
the extra-tropics. The Brewer-Dobson circulation is driven by atmospheric waves
and may be speeding up due to climate change.
Brittle Temperature
The temperature at which a material appears to transform from ductile to brittle
behavior. The characteristic of failure without significant elongation is usually
used as criterion for brittleness The brittle temperature may be based on the statistics for 50% of the fractures above and below this temperature. (This relates to the
problem of balloons failing at the upper troposphere at extremely low
temperatures.)
Glossary and Terminology 337
spectrum. It is similar to the Cherenkov radiation. It is named after Gurgen
Askaryan, a Soviet-Armenian physicist who postulated it in 1962.
The radiation was first observed experimentally in 2000, 38 years after its theoretical prediction. So far the effect has been observed in silica sand, rock salt, ice,
and Earth’s atmosphere.
The effect is of primary interest in using bulk matter to detect ultra-high energy
neutrinos. The Antarctic Impulse Transient Antenna (ANITA) experiment uses antennas attached to a balloon flying over Antarctica to detect the Askaryan radiation produced as cosmic neutrinos travel through the ice. Several experiments have also used
the Moon as a neutrino detector based on detection of the Askaryan radiation.
Blocking
Adhesion between touching layers of plastic film (also called static blocking when
it occurs at room temperature). Adhesion of adjacent layers of plastic film after
conditioning at warm temperatures (also qualified as "thermal blocking").
Breaking Factor
The tensile strength per unit width of films or composites of specified uniform
weight per unit area.
Brewer-Dobson circulation
This is a model of atmospheric circulation, proposed by Alan Brewer in 1949 and
Gordon Dobson in 1956, which attempts to explain why tropical air has less ozone
than polar air, even though the tropical stratosphere is where most atmospheric
ozone is produced. It is a simple circulation model that posits the existence of a
slow current in the winter hemisphere which redistributes air from the tropics to
the extra-tropics. The Brewer-Dobson circulation is driven by atmospheric waves
and may be speeding up due to climate change.
Brittle Temperature
The temperature at which a material appears to transform from ductile to brittle
behavior. The characteristic of failure without significant elongation is usually
used as criterion for brittleness The brittle temperature may be based on the statistics for 50% of the fractures above and below this temperature. (This relates to the
problem of balloons failing at the upper troposphere at extremely low
temperatures.)
Glossary and Terminology 337