Dock

Dock may refer to:

In transportation

In science

In computing

Places

People

Dock (maritime)

A dock (from Dutch dok) is either the area of water between or next to a human-made structure or group of structures involved in the handling of boats or ships, usually on or close to a shore, or the structures themselves. The exact meaning varies among different variants of the English language. "Dock" may also refer to a dockyard or shipyard where the loading, unloading, building, or repairing of ships occurs.

History

The earliest known docks were those discovered in Wadi al-Jarf, an ancient Egyptian harbor dating from 2500 BCE located on the Red Sea coast. Archaeologists also discovered anchors and storage jars near the site. A dock from Lothal in India dates from 2400 BCE and was located away from the main current to avoid deposition of silt. Modern oceanographers have observed that the Harappans must have possessed great knowledge relating to tides in order to build such a dock on the ever-shifting course of the Sabarmati, as well as exemplary hydrography and maritime engineering. This was the earliest known dock found in the world, equipped to berth and service ships. It is speculated that Lothal engineers studied tidal movements, and their effects on brick-built structures, since the walls are of kiln-burnt bricks. This knowledge also enabled them to select Lothal's location in the first place, as the Gulf of Khambhat has the highest tidal amplitude and ships can be sluiced through flow tides in the river estuary. The engineers built a trapezoidal structure, with north-south arms of average 21.8 metres (71.5 ft), and east-west arms of 37 metres (121 ft).

Rumex

The docks and sorrels, genus Rumex L., are a genus of about 200 species of annual, biennial and perennial herbs in the buckwheat family Polygonaceae.

Members of this family are very common perennial herbs growing mainly in the Northern Hemisphere, but various species have been introduced almost everywhere.

Some are nuisance weeds (and are sometimes called dockweed or dock weed), but some are grown for their edible leaves.

Rumex species are used as food plants by the larvae of a number of Lepidoptera species - see list of Lepidoptera that feed on Rumex.

Description

They are erect plants, usually with long taproots. The fleshy to leathery leaves form a basal rosette at the root. The basal leaves may be different from those near the inflorescence. They may or may not have stipules. There are minor leaf veins. The leaf blade margins are entire or crenate.

The usually inconspicuous flowers are carried above the leaves in clusters. The fertile flowers are mostly hermaphrodite, or they may be functionally male or female. The flowers and seeds grow on long clusters at the top of a stalk emerging from the basal rosette; in many species the flowers are green, but in some (such as sheep's sorrel, Rumex acetosella) the flowers and their stems may be brick-red. Each seed is a 3-sided achene, often with a round tubercle on one or all three sides.

Dual (Sampha EP)

Dual is an EP released in July 2013 by British electronic music singer, songwriter and producer Sampha from Morden, South London, United Kingdom.

Critical reception

Dual received positive reviews from most music critics. Zach Kelly of Pitchfork Media stated, "For someone so willing to lay himself this bare as a first impression is rare, but in terms of the music found on 'Dual', nothing could be more natural."

Track listing

All songs written and composed by Sampha. 

Personnel

References

Dual (brand)

Dual (pronounced /duːˈɑːl/ or /-ˈæl/) is a brand name of audio and video electronics.

History

In 1907, brothers Christian and Joseph Steidinger began manufacturing clockwork and gramophone parts in the Black Forest town of St. Georgen. In 1927, Gebrüder Steidinger (Steidinger Bros.) adopted the name Dual in reference to the dual-mode power supplies it pioneered. The power supplies allowed gramophones to be powered from mains electricity or with a wind-up mechanism. Soon thereafter, Dual began producing turntables of its own.

After World War II, Dual became the biggest manufacturer of turntables in Europe, with more than 3,000 employees working in several factories. Throughout the 1970s, 1980s, and 1990s, Dual introduced audio cassette players, VCRs, CD players, and other consumer electronics.

But when Japanese consumer electronics started entering European markets in the 1970s on a large scale, Dual as most other traditional German manufacturers underwent a big crisis: Japanese products usually offered more features at a cheaper price in a much more modern package. Dual went bankrupt in 1982, and was sold to French electronic manufacturer Thomson SA. In 1988, Thomson sold Dual to German manufacturer Schneider Rundfunkwerke AG.

Duality (electrical circuits)

In electrical engineering, electrical terms are associated into pairs called duals. A dual of a relationship is formed by interchanging voltage and current in an expression. The dual expression thus produced is of the same form, and the reason that the dual is always a valid statement can be traced to the duality of electricity and magnetism.

Here is a partial list of electrical dualities:

History

The use of duality in circuit theory is due to Alexander Russell who published his ideas in 1904.

Examples

Constitutive relations

Voltage division — current division

Impedance and admittance