Field (agriculture)

In agriculture, a field is an area of land, enclosed or otherwise, used for agricultural purposes such as cultivating crops or as a paddock or other enclosure for livestock. A field may also be an area left to lie fallow or as arable land.

Many farms have a field border, usually composed of a strip of shrubs and vegetation, used to provide food and cover necessary for the survival of wildlife. It has been found that these borders may lead to an increased variety of animals and plants in the area, but also in some cases a decreased yield of crops.

Language

In Australian and New Zealand English, any agricultural field may be called a paddock. If stock are grazed there, the space may be called a run, e.g. sheep run; cattle run.

Image gallery

A green field or paddock with Hereford cattle

A green field or paddock with Hereford cattle

A summer field

A summer field

Spring fields with trees, Majorca, Spain, 2004

Spring fields with trees, Majorca, Spain, 2004

Field (computer science)

In computer science, data that has several parts, known as a record, can be divided into fields. Relational databases arrange data as sets of database records, also called rows. Each record consists of several fields; the fields of all records form the columns.

In object-oriented programming, field (also called data member or member variable) is the data encapsulated within a class or object. In the case of a regular field (also called instance variable), for each instance of the object there is an instance variable: for example, an Employee class has a Name field and there is one distinct name per employee. A static field (also called class variable) is one variable, which is shared by all instances.

Fixed length

Fields that contain a fixed number of bits are known as fixed length fields. A four byte field for example may contain a 31 bit binary integer plus a sign bit (32 bits in all). A 30 byte name field may contain a persons name typically padded with blanks at the end. The disadvantage of using fixed length fields is that some part of the field may be wasted but space is still required for the maximum length case. Also, where fields are omitted, padding for the missing fields is still required to maintain fixed start positions within a record for instance.

Field (mathematics)

In mathematics, a field is one of the fundamental algebraic structures used in abstract algebra. It is a nonzero commutative division ring, or equivalently a ring whose nonzero elements form an abelian group under multiplication. As such it is an algebraic structure with notions of addition, subtraction, multiplication, and division satisfying the appropriate abelian group equations and distributive law. The most commonly used fields are the field of real numbers, the field of complex numbers, and the field of rational numbers, but there are also finite fields, algebraic function fields, algebraic number fields, p-adic fields, and so forth.

Any field may be used as the scalars for a vector space, which is the standard general context for linear algebra. The theory of field extensions (including Galois theory) involves the roots of polynomials with coefficients in a field; among other results, this theory leads to impossibility proofs for the classical problems of angle trisection and squaring the circle with a compass and straightedge, as well as a proof of the Abel–Ruffini theorem on the algebraic insolubility of quintic equations. In modern mathematics, the theory of fields (or field theory) plays an essential role in number theory and algebraic geometry.

Lava

Lava is the molten rock expelled by a volcano during an eruption. The resulting rock after solidification and cooling is also called lava. The molten rock is formed in the interior of some planets, including Earth, and some of their satellites. The source of the heat that melts the rock within the earth is geothermal energy. When first erupted from a volcanic vent, lava is a liquid at temperatures from 700 to 1,200 °C (1,292 to 2,192 °F).

A lava flow is a moving outpouring of lava, which is created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock. The term lava flow is commonly shortened to lava. Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic and shear thinning properties.

Explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. The word "lava" comes from Italian, and is probably derived from the Latin word labes which means a fall or slide. The first use in connection with extruded magma (molten rock below the Earth's surface) was apparently in a short account written by Francesco Serao on the eruption of Vesuvius between May 14 and June 4, 1737. Serao described "a flow of fiery lava" as an analogy to the flow of water and mud down the flanks of the volcano following heavy rain.

Lava (2001 film)

Lava is a 2001 British black comedy directed by Joe Tucker.

The film competed at the Alexandria International Film Festival, Filmfest Oldenburg, Austin Film Festival and Rome Independent Film Festival in 2000.

References

External links

Greatest Hits TV

Greatest Hits TV was a British satellite TV music channel owned by UltimateHits Limited. The channel is ultimately owned by All Around the World Productions, a British record label who also operate Channel AKA, Clubland TV and Planet Pop.

The channel launched on 29 March 2010 on Sky channel 378 as Lava. Lava specialised in the Indie and rock music genres. Lava's remit was to provide a platform for young rock, pop punk and indie musicians, and features young unsigned music acts from around the United Kingdom. Lava was a sister channel of Channel AKA, which was also owned by Mushroom TV, and replaced Rockworld TV which operated on Sky Channel 378 and closed at 7.00am on 29 March 2010. Both the Lava and Channel AKA formats allowed viewers to decide on the station's playlist through the use of a voting system which enables viewers to watch the videos they want to see.

On 26 April 2011, Lava was rebranded as Greatest Hits TV at 23.45pm. Lava continued on Greatest Hits TV as overnight programming block, called Lava Showcase, between 3.00am and 8.00am, until the autumn 2012 widescreen relaunch of GHTV.