Accretion discs of young stars and protostars radiate in the infrared ; those around neutron stars and black holes in the X-ray part of the spectrum.

Accretion discs surrounding T Tauri stars or Herbig stars are called protoplanetary discs because they are thought to be the progenitors of planetary systems.

Accretion discs around many stellar objects are able to produce jets, although those around a black hole are the fastest and most active.

Accretion discs are common around smaller stars or stellar remnants in a close binary or black holes in the centers of spiral galaxies.

Accretion rates are typically 10 < sup >− 7 </ sup > to 10 < sup >− 9 </ sup > solar masses per year but can vary.

Like classical T Tauri stars, many brown dwarfs are surrounded by disks of gas and dust which accrete onto the brown dwarf .< ref name = uv > First Ultraviolet Spectrum of a Brown Dwarf: Evidence for H < sub > 2 </ sub > Fluorescence and Accretion, John E. Gizis, Harry L. Shipman, and James A. Harvin, Astrophysical Journal 630, # 1 ( September 2005 ), pp. L89 – L91.

* Accretion ( astrophysics )

Artist's conception of a white dwarf star Accretion ( astrophysics ) | accreting hydrogen from a larger companion

* Accretion ( astrophysics )

Accretion power in astrophysics, Third Edition, Cambridge University Press.

Accretion of gas onto the star continues for another 10 million years, before the disk disappears, perhaps being blown away by the young star's solar wind, or perhaps simply ceasing to emit radiation after accretion has ended.

* 4. 54 Ga: Accretion of Earth

# Accretion and differentiation: a period of planetary formation until giant Moon-forming impact event.

Accretion of material onto the protostar continues partially through a circumstellar disc.

The most widely known of these is the Advection Dominated Accretion Flow ( ADAF ), but others exist.

( 2002 ) Chronology of Asteroid Accretion and Differentiation 687 – 695, in Asterois III, Bottke W. F., Cellino A., Paolicchi P., Binzel R. P., eds., University of Arizona Press ( 2002 ), ISBN 0-8165-2281-2

Accretion of gas onto the black hole, probably involving a disk around it, would release energy to power the radio source, itself much larger than the black hole.

Accretion can be thought of as the antonym of amortization.

Accretion, in a corporate finance environment, is essentially the actual value created after a particular transaction.

Notable enterprises which produced discs of such software are BBC PD, Electron User Group and HeadFirst PD.

German brass making crucibles are known from Dortmund dating to the 10th century AD and from Soest and Schwerte in Westphalia dating to around the 13th century confirm Theophilus ' account, as they are open-topped, although ceramic discs from Soest may have served as loose lids which may have been used to reduce zinc evaporation, and have slag on the interior resulting from a liquid process.

Backgammon playing pieces are known variously as checkers, draughts, stones, men, counters, pawns, discs, or chips.

The discs are roughly checker-sized, slightly smaller in diameter than the board's central hole, and often have concave faces to reduce sliding friction.

If there are any enemy discs on the board, a player must make contact, directly or indirectly, with an enemy disc during the shot.

When there are no enemy discs on the board, many ( but not all ) rules also state that a player must shoot for the centre of the board, and a shot disc must finish either completely inside the 15-point guarded ring line, or ( depending on the specifics of the rules ) be inside or touching this line.

Chloroplasts are observable as flat discs usually 2 to 10 micrometres in diameter and 1 micrometre thick.

The CD and its extensions are successful: in 2004, worldwide sales of CD audio, CD-ROM, and CD-R reached about 30 billion discs.

Even higher capacities on non-standard discs ( up to 99 minutes ) are available at least as recordables, but generally the tighter the tracks are squeezed, the worse the compatibility.

* Vehicle ceramic brake discs are resistant to abrasion at high temperatures.

There are different designs of vehicle clutch but most are based on one or more friction discs pressed tightly together or against a flywheel using springs.

There are also 90 minute / 790 MB and 99 minute / 870 MB discs, although they are less common ( and depart from the Orange Book standard outright ).

Some drives use special techniques, such as Plextor's GigaRec or Sanyo's HD-BURN, to write more data onto a given disc ; these techniques are inherently deviations from the Compact Disc ( Red, Yellow, and / or Orange Book ) standards, making the recorded discs proprietary-formatted and not fully compatible with standard CD players and drives.

Therefore, discs with capacities larger than 650 MB, and especially those larger than 700 MB, are less interchangeable among players / drives than standard discs and are not very suitable for archival use, as their readability on future equipment, or even on the same equipment at a future time, is not assured, even under the assumption that the discs will not degrade at all.

Canadian Forces identity discs ( abbreviated " I discs ") are designed to be broken in two in the case of fatality ; the lower half is returned to National Defence Headquarters with the member's personal documents, while the upper half remains on the body.

The phenomenon of optical diffraction sets a limit to the resolution and image quality that a telescope can achieve, which is the effective area of the Airy disc, which limits how close two such discs can be placed.

Bit rot can also be used to describe the phenomenon of data stored in EPROMs and flash memory gradually decaying over the duration of many years, or in the decay of data stored on CD or DVD discs or other types of consumer storage.

Keplerian discs around post-AGB objects: a common phenomenon?

The phenomenon was first described in 1802, as a " special fluid with electrical properties ", by Vasily V. Petrov, a Russian scientist experimenting with a copper-zinc battery consisting of 4200 discs.

The classic 1974 work by Shakura and Sunyaev on thin accretion discs is one of the most often quoted papers in modern astrophysics.

* High-energy astronomy and astrophysics, including supermassive black holes, active galactic nuclei and quasars, X-ray binaries, and accretion discs ;

* Written documents ; for example, clay tablets and discs ( so far in Crete only ), but nothing of more perishable nature, such as skin, papyrus, etc.

The engineering margin that was reserved for manufacturing tolerance has been used for data capacity instead, leaving no tolerance for manufacturing ; for these discs to be truly compliant with the Orange Book standard, the manufacturing process must be perfect.

The standards do require discs to meet precise requirements in order to be called Compact Discs, but the other discs may be called by other names ; if this were not true, no DVD drive could legally bear the Compact Disc logo.

The earlier models were very chemically unstable and this made cyanine based discs unsuitable for archival use ; they could fade and become unreadable in a few years.

However, phthalocyanine is more sensitive than cyanine to writing laser power calibration, meaning that the power level used by the writing laser has to be more accurately adjusted for the disc in order to get a good recording ; this may erode the benefits of dye stability, as marginally written discs ( with higher correctable error rates ) will lose data ( i. e. have uncorrectable errors ) after less dye degradation than well written discs ( with lower correctable error rates ).

There are also illuminated discs meant for nighttime play ; they are made of a phosphorescent plastic or contain battery-powered light-emitting diodes.

Rather, the advantages of the format are seen in the manufacturing process: discs can be stamped ; cylinders could not be until 1901-1902 when the gold moulding process was introduced by Edison.

The three discs are subdivided relating to their content: " Brawlers " features Waits's more upbeat rock and blues songs ; " Bawlers ", his ballads and love songs ; and " Bastards ", songs that fit in neither category, including a number of spoken-word tracks.

Video art can take many forms: recordings that are broadcast, viewed in galleries or other venues, or distributed as video tapes or DVD discs ; sculptural installations, which may incorporate one or more television sets or video monitors, displaying ‘ live ’ or recorded images and sound ; and performances in which video representations are included.

However not all round or spherical discs are rotors ; for example, a ball check valve uses the ball to block reverse flow, but is not a rotor because operating the valve does not involve rotation of the ball.

He demonstrated the world's first colour transmission on 3 July 1928, using scanning discs at the transmitting and receiving ends with three spirals of apertures, each spiral with a filter of a different primary colour ; and three light sources at the receiving end, with a commutator to alternate their illumination.

They were only implemented in Sony's short-lived MD-based camcorder as well as a small number of MultiTrack Recorders ; Sony's MDM-X4, Tascam's 564 ( which could also record using standard MD-Audio discs, albeit only 2 tracks ), and Yamaha's MD-8, MD-4, & MD4S.

New digital soundtracks introduced since the 1990s include Dolby Digital, which is stored between the perforations on the sound side ; SDDS, stored in two redundant strips along the outside edges ( beyond the perforations ); and DTS, in which sound data is stored on separate compact discs synchronized by a timecode track stored on the film just to the right of the analog soundtrack and left of the frame.

The exact number of copies sold has never been audited ; however, a figure of at least 25 million was cited by the Guinness Book of World Records in its category " Phonograph records: Biggest Sellers " from the early 1970s until the 1990s, when the advent of compact discs led to Guinness discontinuing the category.

Through the nineties, the music grew to become one of the most popular genres in France ; in 1997, IAM's release " L ' école du Micro d ' Argent " sold more than 1 million discs, with NTM moving more than 700, 000 copies of their final album " Suprême NTM ".

There are also two different packaging editions for retail, one being in a 4-disc sized jewel case with a simple white cover and the Love Symbol in a colored circle ; the other is all four discs in a round translucent snap jewel case.

As a consequence discs are less prone to the " brake fade " caused when brake components overheat ; and disc brakes recover more quickly from immersion ( wet brakes are less effective ).

Slotted discs are generally not used on standard vehicles because they quickly wear down brake pads ; however, this removal of material is beneficial to race vehicles since it keeps the pads soft and avoids vitrification of their surfaces.