accretion


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accretion

1. Botany the growing together of normally separate plant or animal parts
2. Pathol
a. abnormal union or growing together of parts; adhesion
b. a mass of foreign matter collected in a cavity
3. Law an increase in the share of a beneficiary in an estate, as when a co-beneficiary fails to take his share
4. Astronomy the process in which matter under the influence of gravity is attracted to and increases the mass of a celestial body. The matter usually forms an accretion disc around the accreting object
5. Geology the process in which a continent is enlarged by the tectonic movement and deformation of the earth's crust

accretion

(aggregation) The increase in mass of a body by the addition of smaller bodies that collide and stick to it. The relative velocity of any two colliding bodies must be low enough for them to coalesce on impact rather than fly apart. Once a large enough body forms, its gravitational attraction accelerates the accretion process. Accreting objects in the Universe are numerous and diverse. They include protoplanets, protostars, black holes, and X-ray binaries. The accretion process is thought to occur generally in the form of a disk. Accretion is now assumed to have had an important role in the formation of the planets from swarms of dust grains. In the outer Solar System the grains were like dirty snowflakes and thus accretion was accelerated. See Solar System, origin.

accretion

[ə′krē·shən]
(astronomy)
A process in which a star gathers molecules of interstellar gas to itself by gravitational attraction.
(civil engineering)
Artificial buildup of land due to the construction of a groin, breakwater, dam, or beach fill.
(geology)
Gradual buildup of land on a shore due to wave action, tides, currents, airborne material, or alluvial deposits.
The process whereby stones or other inorganic masses add to their bulk by adding particles to their surfaces. Also known as aggradation.
(meteorology)
The growth of a precipitation particle by the collision of a frozen particle (ice crystal or snowflake) with a supercooled liquid droplet which freezes upon contact.
References in periodicals archive ?
This is really an object that we do not see, but which provided high luminosity due to its strong gravitational field and an accretion disk around it," Elena Seifina said.
A good example of accretion and its application to our industry is a recent case that came out of Region 19 (Washington, Oregon, Alaska, northern Idaho and eastern Montana) of the National Labor Relations Board (NLRB): CPM Development Corp.
Net interest margin, excluding net accretion income, improved 3 basis points compared to the linked quarter.
There are two different black hole scenarios proposed to explain these objects: (1) they contain very "big" black holes that could be more than a thousand times more massive than the Sun (Note 1), or (2) they are relatively small black holes, "little monsters" with masses no more than a hundred times that of the Sun, that shine at luminosities exceeding theoretical limits for standard accretion (called "supercritical (or super-Eddington) accretion," Note 2).
55 per share, diluted, after deduction of USD565,000 in TARP preferred stock dividends and discount accretion.
Blackman and Lucchini determined the minimum power and minimum mass flows that these accretion processes needed to produce to account for the properties of the observed jets.
Accretion and Ejection in AGN Conference (2009: Como, Italy) Ed.
We examined nutrient accretion and the development of thermoregulation and computed an energy budget until fledging.
16 basic and diluted net earnings per share, before adjustment for preferred stock dividends and accretion, for the three months ended June 30, 2010 as compared to $1.
The sellers are willing to assume that risk because they are confident that the NPI development pipeline will demonstrate its worth in the next two years and will provide significant accretion to fund unit holders.
Since 1982, when Chuck Hull invented stereolithography (figure1), have been developed many methods of rapid prototyping by material accretion, which involve building a part by defining its geometry layer by layer, but between the main methods may be mentioned as follows: stereolithography, selective laser-sintering, laminated object manufacturing, fused deposition modeling (Ciucescu & Bontas, 1998).
Because of the great subjectivity required in determining the fair value of an asset retirement obligation (ARO) and its subsequent accretion expense under SFAS No.