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Article of the Week [ about ]

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Coal-fired power plant in Voerde, Germany

A conventional coal-fired power plant produces electricity by burning coal in a steam generator that heats water to produce high pressure and high temperature steam. The steam flows through a series of steam turbines which spin an electrical generator to produce electricity. The exhaust steam from the turbines is cooled, condensed back into water, and returned to the steam generator to start the process over.

Conventional coal-fired power plants are highly complex and custom designed on a large scale for continuous operation 24 hours per day and 365 days per year. Such plants provide most of the electrical energy used in many countries.

Most plants built in the 1980s and early 1990s have a power of around 500 MW (500•10⁶ watt), while many of the modern plants have a power of around 1000 MW. Also the efficiencies (ratio of electrical energy produced to energy released by the coal burned) of conventional coal-fired plants increased from under 35% to close to 45%. Because of the second law of thermodynamics there is a fixed physical limit on the efficiency. By Carnot's law the limit is proportional to the temperature difference of the steam and the cooling water, with the consequence that the efficiency of a plant cannot surpass 50% by much.[more...]

New Draft of the Week [ about ]

The Jass–Belote card games are a family of trick-taking card games in which the Jack ("jass") and Nine of the trump suit are the highest-ranking trumps, and the Tens and Aces of all suits are the next most valuable cards. Games in this family are typically played by 2 or 4 players with the 32 French-suited cards of a piquet pack.

Variants of the basic 2-handed game – known under various names including Klaberjas, Clob and Bela – are played worldwide, especially in Jewish communities. 4-handed Belote with its numerous variants is the French national card game but has spread as far away as Cyprus and Saudi-Arabia. Other notable members of the family include the Swiss and Dutch national card games (Swiss Jass and Dutch Klaverjas). Twenty-Nine, a popular game in South Asia, is a descendent of these games sharing many of their characteristics. [more...]

@@ Line 105: / Line 105: @@
 === Article of the Week <font size=1>[ [[CZ:Article of the Week|about]] ]</font> ===
-A month-long action fought in the [[Vietnam War]] in 1965, the '''[[Battle of the Ia Drang]]''' was a campaign, with two major battles against the a [[division (military)|division]]-sized force from the [[People's Army of Viet Nam]] ([[PAVN]]), although the first U.S. battle is better known in the West.  It is an especially informative topic, since, in addition to the U.S. reports that long have been available, some of the key commanders on both the North Vietnamese and U.S. sides have met as friends, and discussed the different perspectives. South Vietnamese reporting is also available.
+{{Image|Voerde Coal-fired Power Plant.jpg|right|200px|Coal-fired power plant in Voerde, Germany}}
+A '''[[conventional coal-fired power plant]]''' produces [[electricity]] by [[Combustion|burning]] [[coal]] in a [[Boiler|steam generator]] that heats water to produce high pressure  and high temperature [[steam]]. The steam flows through a series of [[steam turbine]]s which spin an [[electrical generator]] to produce electricity. The exhaust steam from the turbines is cooled, [[Condensation|condensed]] back into water, and returned to the steam generator to start the process over.
-The engagement took place in the South Vietnamese [[II Corps tactical zone]] area, headed by MG [[Vinh Loc]].
+Conventional coal-fired power plants are highly complex and custom designed on a large scale for continuous operation 24 hours per day and 365 days per year. Such plants provide most of the electrical energy used in many countries.
-<font size=1>[[Battle of the Ia Drang|['''more...''']]]</font>
+Most plants built in the 1980s and early 1990s have a power of around 500 MW (500•10<sup>6</sup> [[watt (unit)|watt]]), while many of the modern plants have a power of around 1000 MW. Also the efficiencies (ratio of electrical energy produced to energy released by the coal burned) of conventional coal-fired plants increased from  under 35% to close to 45%.  Because of the [[second law of thermodynamics]] there is a fixed physical limit on the efficiency. By [[Carnot's law]] the limit is proportional to the temperature difference of the steam and the cooling water, with the consequence that the efficiency of a plant cannot surpass 50% by much.<font size=1>[[Conventional coal-fired power plant|['''more...''']]]</font>
 === New Draft of the Week <font size=1>[ [[CZ:New Draft of the Week|about]] ]</font> ===
-{{Image|Leptotes bicolor.jpg|right|150px|Leptotes bicolor}}
+The '''[[Jass–Belote card games]]''' are a family of [[trick-taking game|trick-taking]] [[card game]]s in which the Jack ("jass") and Nine of the trump suit are the highest-ranking [[trump]]s, and the Tens and Aces of all suits are the next most valuable cards. Games in this family are typically played by 2 or 4 players with the 32 French-suited cards of a [[piquet pack]].
-'''''[[Leptotes]]''''' is a genus of [[orchid]]s formed by nine small species that grow in the dry jungles of south and southeast [[Brazil]], and also in [[Paraguay]] or [[Argentina]]. They are small [[epiphytic]] plants of [[caespitific]] growth, that sometimes resemble little ''[[Brassavola]]'', as they share the same type of thin terete leaves, however, they are more closely related to ''[[Loefgrenianthus]]''.
-Some species of ''Leptotes'' are widely cultivated and form showy displays when completely in bloom although they are not among the easiest to grow. The majority of the species are not cultivated and some are so rare to be almost unknown; five of the species have only recently been described since 2000.  Beside being cultivated for their ornamental value, there are records of the flowers and fruits of ''[[Leptotes bicolor]]'' being used as a substitute for [[vanilla]] in milk, ice cream, tea and candies. <font size=1>[[Leptotes|['''more...''']]]</font>
+Variants of the basic 2-handed game – known under various names including '''Klaberjas''', '''Clob''' and '''Bela''' – are played worldwide, especially in Jewish communities. 4-handed '''Belote''' with its numerous variants is the French national card game but has spread as far away as Cyprus and Saudi-Arabia. Other notable members of the family include the Swiss and Dutch national card games (Swiss '''Jass''' and Dutch '''Klaverjas'''). [[Twenty-Nine (card game)|Twenty-Nine]], a popular game in South Asia, is a descendent of these games sharing many of their characteristics. <font size=1>[[Jass–Belote card games|['''more...''']]]</font>
 |}