- published: 11 Dec 2014
- views: 11446651
A dynamo (from the Greek word dynamis; meaning power), originally another name for an electrical generator, generally means a generator that produces direct current with the use of a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating-current alternator, and the rotary converter. Today, the simpler alternator dominates large scale power generation, for efficiency, reliability and cost reasons. A dynamo has the disadvantages of a mechanical commutator. Also, converting alternating to direct current using power rectification devices (hollow state or more recently solid state) is effective and usually economic.
The word still has some regional usage as a replacement for the word generator. A small electrical generator built into the hub of a bicycle wheel to power lights is called a Hub dynamo, although these are invariably AC devices.[citation needed]
In the United States and Canada, a cookie is a small, flat, baked treat, usually containing fat, flour, eggs and sugar. In most English-speaking countries outside North America, the most common word for this is biscuit; in many regions both terms are used, while in others the two words have different meanings. A cookie is a plain bun in Scotland, while in the United States a biscuit is a kind of quick bread similar to a scone. In the United Kingdom, a cookie is referred to as a biscuit, although some types of cookies maintain this name, such as the American-inspired Maryland Cookies, which are also sold there. In South Africa they are called biscuits, and the word cookie refers to cupcakes.
Its American name derives from the Dutch word koekje or (informal) koekie which means little cake, and arrived in American English through the Dutch in North America.
According to the Scottish National Dictionary, its Scottish name derives from the diminutive form (+ suffix -ie) of the word cook, giving the Middle Scots cookie, cooky or cu(c)kie. It also gives an alternative etymology, from the Dutch word koekje, the diminutive of koek, a cake. There was much trade and cultural contact across the North Sea between the Low Countries and Scotland during the Middle Ages, which can also be seen in the history of curling and, perhaps, golf.
Douglas may refer to: