For the Swedish ice hockey player, see Viktor Svedberg

Viktor Svedberg

Viktor Svedberg is a Swedish professional ice hockey defenceman who currently plays for Frölunda HC of the Elitserien. In 2010 he won the...

.

A svedberg (symbol S, sometimes Sv, not to be confused with Sv for the SI

Si

Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...

 unit sievert

Sievert

The sievert is the International System of Units SI derived unit of dose equivalent radiation. It attempts to quantitatively evaluate the biological effects of ionizing radiation as opposed to just the absorbed dose of radiation energy, which is measured in gray...

 as well as the non-SI sverdrup

Sverdrup

The sverdrup, named in honour of the pioneering oceanographer Harald Sverdrup, is a unit of measure of volume transport. It is used almost exclusively in oceanography, to measure the transport of ocean currents. Its symbol is Sv. Note that the sverdrup is not an SI unit, and that its symbol...

) is a non-SI

Si

Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...

 physical

Physics

Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

 unit used for sedimentation coefficient

Sedimentation coefficient

The sedimentation coefficient s of a particle is used to characterize its behaviour in sedimentation processes, notably centrifugation. It is defined as the ratio of a particle's sedimentation velocity to the acceleration that is applied to it .The sedimentation speed v_t is also known as the...

s.  It characterizes the behaviour of a particle type in sedimentation

Sedimentation

Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained, and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration...

 processes, notably centrifugation

Centrifugation

Centrifugation is a process that involves the use of the centrifugal force for the sedimentation of mixtures with a centrifuge, used in industry and in laboratory settings. More-dense components of the mixture migrate away from the axis of the centrifuge, while less-dense components of the mixture...

.  The svedberg is technically a measure of time, and is defined as exactly 10^-13 second

Second

The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....

s (100 fs).

Conventionally all sedimentation coefficients are expressed in the Svedberg units (i.e., 100 fs).  The sedimentation coefficient is the ratio of the speed of a substance in a centrifuge to its acceleration in comparable units.  A substance with a sedimentation coefficient of 26S (26x10^-13 s) will travel at 26 microns per second (26x10^-6 m/s) under the influence of an acceleration of a million gravities (10⁷ m/s²).  Centrifugal acceleration is given as rω²; where r is the radial distance from the rotation axis and ω is the angular velocity

Angular velocity

In physics, the angular velocity is a vector quantity which specifies the angular speed of an object and the axis about which the object is rotating. The SI unit of angular velocity is radians per second, although it may be measured in other units such as degrees per second, revolutions per...

 in radians per second.

The unit is named after the Swedish

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

 chemist

Chemist

A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...

 Theodor Svedberg

Theodor Svedberg

Theodor H. E. Svedberg was a Swedish chemist and Nobel laureate, active at Uppsala University. His work with colloids supported the theories of Brownian motion put forward by Einstein and the Polish geophysicist Marian Smoluchowski...

 (1884-1971), winner of the Nobel prize

Nobel Prize

The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...

 in chemistry

Chemistry

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

 in 1926 for his work in the chemistry of colloid

Colloid

A colloid is a substance microscopically dispersed evenly throughout another substance.A colloidal system consists of two separate phases: a dispersed phase and a continuous phase . A colloidal system may be solid, liquid, or gaseous.Many familiar substances are colloids, as shown in the chart below...

s and his invention of the ultracentrifuge

Ultracentrifuge

The ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as 2,000,000 g . There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge...

.

Bigger particles tend to sediment faster and thus have higher svedberg values.  Sedimentation coefficients are, however, not additive.  Sedimentation rate does not depend only on the mass or volume of a particle, and when two particles bind together there is inevitably a loss of surface area.  Thus when measured separately they will have svedberg values that may not add up to that of the bound particle.

The svedberg is the most important measure used to distinguish ribosome

Ribosome

A ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....

s, which are important in phylogenetic

Phylogenetics

In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...

studies.

External links

• Svedberg unit - Nobelprize.org