Martin Knudsen
Encyclopedia
This article is about the Danish physicist Martin Knudsen. For the Norwegian footballer, see Martin Knudsen (footballer)
.
Martin Hans Christian Knudsen (February 15, 1871 in Hasmark – May 27, 1949 in Copenhagen) was a Danish
physicist who taught and conducted research at the Technical University of Denmark
He is primarily known for his study of molecular gas flow and the development of the Knudsen cell
, which is a primary component of molecular beam epitaxy
systems.
Knudsen received the University's gold medal in 1895 and earned his master's degree in physics the following year. He became lecturer in physics at the University in 1901 and professor in 1912, when C. Christiansen (1843-1917) retired. He held this post until his own retirement in 1941.
Knudsen was renowned for his work on kinetic-molecular theory and low-pressure phenomena in gases. His name is associated with the Knudsen flow
, Knudsen number
, Knudsen layer
and Knudsen gas
es. Also there is the Knudsen Equation; two instruments, the Knudsen absolute manometer and Knudsen gauge; and one gas pump that operates without moving parts, the Knudsen pump
. His book, The Kinetic Theory of Gases (London, 1934), contains the main results of his research.
Knudsen was also very active in physical oceanography
, developing methods of defining properties of seawater. He was editor of Hydrological Tables (Copenhagen-London, 1901).
He was awarded the Alexander Agassiz Medal
of the U.S. National Academy of Sciences
in 1935.
Martin Knudsen (footballer)
Martin Knudsen is a footballer from Stavanger who plays for Staal.He started his senior career in Viking FK....
.
Martin Hans Christian Knudsen (February 15, 1871 in Hasmark – May 27, 1949 in Copenhagen) was a Danish
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
physicist who taught and conducted research at the Technical University of Denmark
Technical University of Denmark
The Technical University of Denmark , often simply referred to as DTU, is a university just north of Copenhagen, Denmark. It was founded in 1829 at the initiative of Hans Christian Ørsted as Denmark's first polytechnic, and is today ranked among Europe's leading engineering institutions, and the...
He is primarily known for his study of molecular gas flow and the development of the Knudsen cell
Knudsen Cell
In crystal growth, Knudsen Cells are often used as sources evaporators for relatively low partial pressure elementary sources...
, which is a primary component of molecular beam epitaxy
Molecular beam epitaxy
Molecular beam epitaxy is one of several methods of depositing single crystals. It was invented in the late 1960s at Bell Telephone Laboratories by J. R. Arthur and Alfred Y. Cho.-Method:...
systems.
Knudsen received the University's gold medal in 1895 and earned his master's degree in physics the following year. He became lecturer in physics at the University in 1901 and professor in 1912, when C. Christiansen (1843-1917) retired. He held this post until his own retirement in 1941.
Knudsen was renowned for his work on kinetic-molecular theory and low-pressure phenomena in gases. His name is associated with the Knudsen flow
Knudsen flow
Knudsen flow describes the movement of fluids with a high Knudsen number, that is, where the characteristic dimension of the flow space is of the same or smaller order of magnitude as the mean free path.-Separation processes using Knudsen Flow:...
, Knudsen number
Knudsen number
The Knudsen number is a dimensionless number defined as the ratio of the molecular mean free path length to a representative physical length scale. This length scale could be, for example, the radius of a body in a fluid...
, Knudsen layer
Knudsen layer
The Knudsen layer, also known as evaporation layer, is the thin layer between liquid and vapour. It is named after Danish physicist Martin Knudsen .-Definition:...
and Knudsen gas
Knudsen gas
A Knudsen gas is a model for gases where particle collisions are ignored, as opposed to the Lorenz gas where collisions are considered. In these gases the mean free path of molecules is bigger than the receptacle where the gas is contained...
es. Also there is the Knudsen Equation; two instruments, the Knudsen absolute manometer and Knudsen gauge; and one gas pump that operates without moving parts, the Knudsen pump
Knudsen pump
The Knudsen pump is a gas pump that utilizes no moving parts. Instead it uses the so-called thermal transpiration, the phenomenon that gas molecules drift from the cold end to the hot end of a narrow channel. This thermal transpiration flow is induced when the boundary walls of the pump have a...
. His book, The Kinetic Theory of Gases (London, 1934), contains the main results of his research.
Knudsen was also very active in physical oceanography
Oceanography
Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...
, developing methods of defining properties of seawater. He was editor of Hydrological Tables (Copenhagen-London, 1901).
He was awarded the Alexander Agassiz Medal
Alexander Agassiz Medal
The Alexander Agassiz Medal is awarded by the U.S. National Academy of Sciences for an original contribution in the science of oceanography. It was established by Sir John Murray in honor of his friend Alexander Agassiz.-Recipients:-References:NotesA...
of the U.S. National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
in 1935.