|
Annular
Annulus (or anulus) or annular indicates a ring- or donut-shaped area or structure. It may refer to: Human anatomy * ''Anulus fibrosus disci intervertebralis'', spinal structure * Annulus of Zinn, a.k.a. annular tendon or ''anulus tendineus communis'', around the optic nerve * Annular ligament (other) * ''Digitus anularis'', a.k.a. ring finger * ''Anulus ciliaris'', a.k.a. ciliary body * ''Anulus femoralis'', a.k.a. femoral ring * ''Anulus inguinalis superficialis'', a.k.a. superficial inguinal ring * ''Anulus inguinalis profundus'', a.k.a. deep inguinal ring * ''Anuli fibrosi cordis'', a.k.a. fibrous rings of heart * ''Anulus umbilicalis '', a.k.a. umbilical ring Biology * Annulus (botany), structure on fern and moss sporangia * Annulus (mycology), structure on mushroom * Annulus (zoology), an external circular ring Other * Annulus (construction), outer gear ring in an epicyclic gearing * Annular lake, a ring-shaped lake caused by meteor impact * Annulus (mathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annular Tropical Cyclone
An annular tropical cyclone is a tropical cyclone that features a normal to large, symmetric eye surrounded by a thick and uniform ring of intense convection, often having a relative lack of discrete rainbands, and bearing a symmetric appearance in general. As a result, the appearance of an annular tropical cyclone can be referred to as akin to a tire or doughnut. Annular characteristics can be attained as tropical cyclones intensify; however, outside the processes that drive the transition from asymmetric systems to annular systems and the abnormal resistance to negative environmental factors found in storms with annular features, annular tropical cyclones behave similarly to asymmetric storms. Most research related to annular tropical cyclones is limited to satellite imagery and aircraft reconnaissance as the conditions thought to give rise to annular characteristics normally occur over open water, well removed from landmasses where surface observations are possible. Characte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combustor
A combustor is a component or area of a gas turbine, ramjet, or scramjet engine where combustion takes place. It is also known as a burner, burner can, combustion chamber or flame holder. In a gas turbine engine, the ''combustor'' or combustion chamber is fed high-pressure air by the compression system. The combustor then heats this air at constant pressure as the fuel/air mix burns. As it burns the fuel/air mix heats and rapidly expands. The burned mix is exhausted from the combustor through the nozzle guide vanes to the turbine. In the case of ramjet or scramjet engines, the exhaust is directly fed out through the nozzle. A combustor must contain and maintain stable combustion despite very high air flow rates. To do so combustors are carefully designed to first mix and ignite the air and fuel, and then mix in more air to complete the combustion process. Early gas turbine engines used a single chamber known as a can-type combustor. Today three main configurations exist: can, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annular Eclipse
A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of Earth, totally or partially. Such an alignment occurs approximately every six months, during the eclipse season in its new moon phase, when the Moon's orbital plane is closest to the plane of Earth's orbit. In a total eclipse, the disk of the Sun is fully obscured by the Moon. In partial and annular eclipses, only part of the Sun is obscured. Unlike a lunar eclipse, which may be viewed from anywhere on the night side of Earth, a solar eclipse can only be viewed from a relatively small area of the world. As such, although total solar eclipses occur somewhere on Earth every 18 months on average, they recur at any given place only once every 360 to 410 years. If the Moon were in a perfectly circular orbit and in the same orbital plane as Earth, there would be total solar eclipses once a month, at every new moon. Instead, because the Moon's orbit is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annular Blowout Preventer
A blowout preventer (BOP) (pronounced B-O-P) is a specialized valve or similar mechanical device, used to seal, control and monitor oil and gas wells to prevent blowouts, the uncontrolled release of crude oil or natural gas from a well. They are usually installed in stacks of other valves. The earliest blowout preventers; Regan Type K Annulars were used, beginning in the 1930s to cope with extreme erratic pressures and uncontrolled flow ( formation kick) emanating from a well reservoir during drilling. Kicks can lead to a potentially catastrophic event known as a blowout. In addition to controlling the downhole (occurring in the drilled hole) pressure and the flow of oil and gas, blowout preventers are intended to prevent tubing (e.g. drill pipe and well casing), tools, and drilling fluid from being blown out of the wellbore (also known as bore hole, the hole leading to the reservoir) when a blowout threatens. Blowout preventers are critical to the safety of crew, rig (th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Finger
The ring finger, third finger, fourth finger, leech finger, or annulary is the fourth digit of the human hand, located between the middle finger and the little finger. Sometimes the term ring finger only refers to the fourth digit of a left-hand, so named for its traditional association with wedding rings in many societies, although not all use this digit as the ring finger. Traditionally, a wedding ring was worn only by the bride or wife, but in recent times more men also wear a wedding ring. It is also the custom in some societies to wear an engagement ring on the ring finger. In anatomy, the ring finger is called ''digitus medicinalis'', ''the fourth digit'', ''digitus annularis'', ''digitus quartus'', or ''digitus IV''. In Latin, the word ''anulus'' means "ring", ''digitus'' means "digit", and ''quartus'' means "fourth". Etymology The origin of the selection of the fourth digit as the ring finger is not definitively known. According to László A. Magyar, the names of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulation
In organic chemistry, annulation (; occasionally annelation) is a chemical reaction in which a new ring is constructed on a molecule. : Examples are the Robinson annulation, Danheiser annulation and certain cycloadditions. Annular molecules are constructed from side-on condensed cyclic segments, for example helicenes and acenes. In transannulation a bicyclic molecule is created by intramolecular carbon-carbon bond formation in a large monocyclic ring. An example is the samarium(II) iodide induced ketone - alkene cyclization of ''5-methylenecyclooctanone'' which proceeds through a ketyl intermediate: : Benzannulation The term benzannulated compounds refers to derivatives of cyclic compounds (usually aromatic) which are fused to a benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulus (mycology)
An annulus is the ring-like or collar-like structure sometimes found on the Stipe (mycology), stipe of some species of mushrooms. The annulus represents the remnants of the partial veil, after it has ruptured to expose the gill (mushroom), gills or other spore-producing surface. It can also be called a ring which is what the Latin word annulus directly translates as. The modern usage of the Latin word originates from the early days of botany and mycology when species Species description, descriptions were only written in Latin. Outside of the formal setting of scientific publications which still have a Latin requirement, it will often just be referred to as a ring or stem ring in field guides and on identification websites. Ring descriptions The way in which the structure and appearance of rings is described can vary with author and the description may only note the existence of a ring without providing specific information in cases where the ring lacks any notable features that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulus (firestop)
The annulus, or annular space, is the space between a penetrant and anything that surrounds it, such as the sides of an opening or a sleeve A sleeve (, a word allied to '' slip'', cf. Dutch ) is the part of a garment that covers the arm, or through which the arm passes or slips. The sleeve is a characteristic of fashion seen in almost every country and time period, across a myri ..., depending on the case. It is named after the corresponding geometric concept due to its shape. References External links External examples of the use of the term. Annulus, a term used within a firestop patentAnnulus, as used in UL System C-AJ-1557 Firestop System, Configuration A {{Fire protection, state=collapsed Passive fire protection Firestops ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulus (mathematics)
In mathematics, an annulus (: annuli or annuluses) is the region between two concentric circles. Informally, it is shaped like a ring or a hardware washer. The word "annulus" is borrowed from the Latin word ''anulus'' or ''annulus'' meaning 'little ring'. The adjectival form is ''annular'' (as in annular eclipse). The open annulus is topologically equivalent to both the open cylinder and the punctured plane. Area The area of an annulus is the difference in the areas of the larger circle of radius and the smaller one of radius : :A = \pi R^2 - \pi r^2 = \pi\left(R^2 - r^2\right) = \pi (R+r)(R-r) . The area of an annulus is determined by the length of the longest line segment within the annulus, which is the chord tangent to the inner circle, in the accompanying diagram. That can be shown using the Pythagorean theorem since this line is tangent to the smaller circle and perpendicular to its radius at that point, so and are sides of a right-angled triangle with hyp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annular Lake
An impact crater lake is a lake inside a depression caused by the impact of a meteor. It is also known as an annular lake in cases where the water body is shaped like a ring, as many impact crater lakes are. Examples One of the largest impact crater lakes is Manicouagan Reservoir, Lake Manicouagan in Canada; the crater is a multiple-ring structure about across, with its diameter inner ring its most prominent feature; it contains a diameter annular lake, surrounding an inner island plateau, René-Levasseur Island. It is Earth's sixth-largest confirmed impact crater according to rim-to-rim diameter. List See also * Volcanic crater lake References Impact crater lakes, {{Geo-term-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulus (construction)
Annulus (or anulus) or annular indicates a ring- or donut-shaped area or structure. It may refer to: Human anatomy * ''Anulus fibrosus disci intervertebralis'', spinal structure * Annulus of Zinn, a.k.a. annular tendon or ''anulus tendineus communis'', around the optic nerve * Annular ligament (other) * ''Digitus anularis'', a.k.a. ring finger * ''Anulus ciliaris'', a.k.a. ciliary body * ''Anulus femoralis'', a.k.a. femoral ring * ''Anulus inguinalis superficialis'', a.k.a. superficial inguinal ring * ''Anulus inguinalis profundus'', a.k.a. deep inguinal ring * ''Anuli fibrosi cordis'', a.k.a. fibrous rings of heart * ''Anulus umbilicalis '', a.k.a. umbilical ring Biology * Annulus (botany), structure on fern and moss sporangia * Annulus (mycology), structure on mushroom * Annulus (zoology), an external circular ring Other * Annulus (construction), outer gear ring in an epicyclic gearing * Annular lake, a ring-shaped lake caused by meteor impact * Annulus (mathem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anulus Fibrosus Disci Intervertebralis
An intervertebral disc (British English), also spelled intervertebral disk (American English), lies between adjacent vertebrae in the vertebral column. Each disc forms a fibrocartilaginous joint (a symphysis), to allow slight movement of the vertebrae, to act as a ligament to hold the vertebrae together, and to function as a shock absorber for the spine. Structure Intervertebral discs consist of an outer fibrous ring, the ''anulus (or annulus) fibrosus disci intervertebralis'', which surrounds an inner gel-like center, the ''nucleus pulposus''. The ''anulus fibrosus'' consists of several layers (laminae) of fibrocartilage made up of both type I and type II collagen. Type I is concentrated toward the edge of the ring, where it provides greater strength. The stiff laminae can withstand compressive forces. The fibrous intervertebral disc contains the ''nucleus pulposus'' and this helps to distribute pressure evenly across the disc. This prevents the development of stress conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
