A central heating system provides warmth to the whole interior of a building (or portion of a building) from one point to multiple rooms. When combined with other systems in order to control the building climate, the whole system may be a HVAC (heating, ventilation and air conditioning) system.
Central heating differs from local heating in that the heat generation occurs in one place, such as a furnace room in a house or a mechanical room in a large building (though not necessarily at the "central" geometric point). The most common method of heat generation involves the combustion of fossil fuel in a furnace or boiler. The resultant heat then gets distributed: typically by forced-air through ductwork, by water circulating through pipes, or by steam fed through pipes. Increasingly, buildings utilize solar-powered heat sources, in which case the distribution system normally uses water circulation.
In much of northern Europe and in urban portions of Russia, where people seldom require air conditioning in homes due to the temperate climate, most new housing comes with central heating installed. Such areas normally use gas heaters, district heating, or oil-fired systems. In the western and southern United States natural-gas-fired central forced-air systems occur most commonly; these systems and central-boiler systems both occur in the far northern regions of the USA. Steam-heating systems, fired by coal, oil or gas, feature in the USA, Russia and Europe: primarily for larger buildings. Electrical heating systems occur less commonly and are practical only with low-cost electricity or when geothermal heat pumps are used. Considering the combined system of central generating plant and electric resistance heating, the overall efficiency will be less than for direct use of fossil fuel for space heating.
History
The Summer Palace of Peter the Great in St. Petersburg, one of the first buildings to incorporate the modern-type hydrologic central heatingSome buildings in the Roman Empire used central heating systems, conducting air heated by furnaces through empty spaces under the floors and out of pipes in the walls — a system known as a hypocaust.[1] A similar system of central heating was used in ancient Korea, where it is known as ondol. It is thought that the ondol system dates back to the Koguryo or Three Kingdoms (37 BC-AD 668) period when excess heat from stoves were used to warm homes.
In the early medieval Alpine upland, a simpler central heating system where heat travelled through underfloor channels from the furnace room replaced the Roman hypocaust at some places. In Reichenau Abbey a network of interconnected underfloor channels heated the 300 m² large assembly room of the monks during the winter months. The degree of efficiency of the system has been calculated at 90%.
In the 13th century, the Cistercian monks revived central heating in Christian Europe using river diversions combined with indoor wood-fired furnaces. The well-preserved Royal Monastery of Our Lady of the Wheel (founded 1202) on the Ebro River in the Aragon region of Spain provides an excellent example of such an application.
The Roman hypocaust continued to be used on a smaller scale during late Antiquity and by the Umayyad caliphate, while later Muslim builder employed a simpler system of underfloor pipes.
By about 1700 Russian engineers had started designing hydrologically based systems for central heating. The Summer Palace (1710–1714) of Peter the Great in Saint Petersburg provides the best extant example. Slightly later, in 1716, came the first use of water in Sweden to distribute heat in buildings. Martin Triewald, a Swedish engineer, used this method for a greenhouse at Newcastle upon Tyne. Jean Simon Bonnemain (1743–1830), a French architect, introduced the technique to industry on a cooperative, at Château du Pêcq, near Paris.
Angier March Perkins developed and installed some of the earliest steam-heating systems in the 1830s. The first was installed in the home of Governor of the Bank of England John Horley Palmer so that he could grow grapes in England's cold climate.[5]
Franz San Galli, a Polish-born Russian businessman living in St. Petersburg, invented the radiator between 1855-1857, which was a major step in the final shaping of modern central heating.Wiki
I'm especially grateful for it on a day like this -but also for the Oil Man , and the Oil distributer, and the tanker driver, tanker mechanic, sales person, heating engineer etc ,etc,etc.Thanks to them and the God who made them
Wednesday 14 December 2011
Monday 12 December 2011
Saturday 10 December 2011
Youtube
YouTube is a video-sharing website, created by three former PayPal employees in February 2005, on which users can upload, view and share videos.[3]
The company is based in San Bruno, California, and uses Adobe Flash Video and HTML5[4] technology to display a wide variety of user-generated video content, including movie clips, TV clips, and music videos, as well as amateur content such as video blogging and short original videos. Most of the content on YouTube has been uploaded by individuals, although media corporations including CBS, BBC, VEVO, Hulu, and other organizations offer some of their material via the site, as part of the YouTube partnership program.[5]
Unregistered users may watch videos, and registered users may upload an unlimited number of videos. Videos that are considered to contain potentially offensive content are available only to registered users 18 years old and older.
In November 2006, YouTube, LLC was bought by Google Inc. for US$1.65 billion, and now operates as a subsidiary of Google.
YouTube was founded by Chad Hurley, Steve Chen, and Jawed Karim, who were all early employees of PayPal.[6] Hurley had studied design at Indiana University of Pennsylvania, while Chen and Karim studied computer science together at the University of Illinois at Urbana-Champaign.[7]
According to a story that has often been repeated in the media, Hurley and Chen developed the idea for YouTube during the early months of 2005, after they had experienced difficulty sharing videos that had been shot at a dinner party at Chen's apartment in San Francisco. Karim did not attend the party and denied that it had occurred, while Hurley commented that the idea that YouTube was founded after a dinner party "was probably very strengthened by marketing ideas around creating a story that was very digestible".[8]
YouTube began as a venture-funded technology startup, primarily from a $11.5 million investment by Sequoia Capital between November 2005 and April 2006.[9] YouTube's early headquarters were situated above a pizzeria and Japanese restaurant in San Mateo, California.[10] The domain name www.youtube.com was activated on February 14, 2005, and the website was developed over the subsequent months.[11]
The first YouTube video was entitled Me at the zoo, and shows founder Jawed Karim at the San Diego Zoo.[12] The video was uploaded on April 23, 2005, and can still be viewed on the site.[13]
YouTube offered the public a beta test of the site in May 2005, six months before the official launch in November 2005. The site grew rapidly, and in July 2006 the company announced that more than 65,000 new videos were being uploaded every day, and that the site was receiving 100 million video views per day.[14] According to data published by market research company comScore, YouTube is the dominant provider of online video in the United States, with a market share of around 43 percent and more than 14 billion videos viewed in May 2010.[15] YouTube says that over 48 hours of new videos are uploaded to the site every minute, and that around three quarters of the material comes from outside the US.[16][17] It is estimated that in 2007 YouTube consumed as much bandwidth as the entire Internet in 2000.[18] Alexa ranks YouTube as the third most visited website on the Internet, behind Google and Facebook.[19]
The choice of the name www.youtube.com led to problems for a similarly named website, www.utube.com. The owner of the site, Universal Tube & Rollform Equipment, filed a lawsuit against YouTube in November 2006 after being overloaded on a regular basis by people looking for YouTube. Universal Tube has since changed the name of its website to www.utubeonline.com.[20][21] In October 2006, Google Inc. announced that it had acquired YouTube for $1.65 billion in Google stock, and the deal was finalized on November 13, 2006.[22] Google does not provide detailed figures for YouTube's running costs, and YouTube's revenues in 2007 were noted as "not material" in a regulatory filing.[23] In June 2008, a Forbes magazine article projected the 2008 revenue at $200 million, noting progress in advertising sales.[24]
In November 2008, YouTube reached an agreement with MGM, Lions Gate Entertainment, and CBS, allowing the companies to post full-length films and television episodes on the site, accompanied by advertisements in a section for US viewers called "Shows". The move was intended to create competition with websites such as Hulu, which features material from NBC, Fox, and Disney.[25][26] In November 2009, YouTube launched a version of "Shows" available to UK viewers, offering around 4,000 full-length shows from more than 60 partners.[27] In January 2010, YouTube introduced an online film rentals service,[28] which is currently available only to users in the US, Canada and the UK.[29][30] The service offers over 6,000 films.[31]
YouTube's current headquarters in San Bruno, CaliforniaIn March 2010, YouTube began free streaming of certain content, including 60 cricket matches of the Indian Premier League. According to YouTube, this was the first worldwide free online broadcast of a major sporting event.[32]
On March 31, 2010, the YouTube website launched a new design, with the aim of simplifying the interface and increasing the time users spend on the site. Google product manager Shiva Rajaraman commented: "We really felt like we needed to step back and remove the clutter."[33] In May 2010, it was reported that YouTube was serving more than two billion videos a day, which it described as "nearly double the prime-time audience of all three major US television networks combined".[34] In May 2011, YouTube reported in its company blog that the site was receiving more than three billion views per day.[16]
In October 2010, Hurley announced that he would be stepping down as chief executive officer of YouTube to take an advisory role, and that Salar Kamangar would take over as head of the company.[35]
In April 2011, James Zern, a YouTube software engineer, revealed that 30 percent of videos accounted for 99 percent of views on the site.[36]
In November 2011, the Google+ social networking site was integrated directly with YouTube and the Chrome web browser, allowing YouTube videos to be viewed from within the Google+ interface.[37] In December 2011, YouTube launched a new version of the site interface, with the video channels displayed in a central column on the home page, similar to the news feeds of social networking sites.[38] At the same time, a new version of the YouTube logo was introduced with a darker shade of red, the first change in design since October 2006.[39]
Naming your song on Youtube and then listening to and watching your favourite artist perform is truly a great feat of modern technology.
It has given me hours of pleasure.
The company is based in San Bruno, California, and uses Adobe Flash Video and HTML5[4] technology to display a wide variety of user-generated video content, including movie clips, TV clips, and music videos, as well as amateur content such as video blogging and short original videos. Most of the content on YouTube has been uploaded by individuals, although media corporations including CBS, BBC, VEVO, Hulu, and other organizations offer some of their material via the site, as part of the YouTube partnership program.[5]
Unregistered users may watch videos, and registered users may upload an unlimited number of videos. Videos that are considered to contain potentially offensive content are available only to registered users 18 years old and older.
In November 2006, YouTube, LLC was bought by Google Inc. for US$1.65 billion, and now operates as a subsidiary of Google.
YouTube was founded by Chad Hurley, Steve Chen, and Jawed Karim, who were all early employees of PayPal.[6] Hurley had studied design at Indiana University of Pennsylvania, while Chen and Karim studied computer science together at the University of Illinois at Urbana-Champaign.[7]
According to a story that has often been repeated in the media, Hurley and Chen developed the idea for YouTube during the early months of 2005, after they had experienced difficulty sharing videos that had been shot at a dinner party at Chen's apartment in San Francisco. Karim did not attend the party and denied that it had occurred, while Hurley commented that the idea that YouTube was founded after a dinner party "was probably very strengthened by marketing ideas around creating a story that was very digestible".[8]
YouTube began as a venture-funded technology startup, primarily from a $11.5 million investment by Sequoia Capital between November 2005 and April 2006.[9] YouTube's early headquarters were situated above a pizzeria and Japanese restaurant in San Mateo, California.[10] The domain name www.youtube.com was activated on February 14, 2005, and the website was developed over the subsequent months.[11]
The first YouTube video was entitled Me at the zoo, and shows founder Jawed Karim at the San Diego Zoo.[12] The video was uploaded on April 23, 2005, and can still be viewed on the site.[13]
YouTube offered the public a beta test of the site in May 2005, six months before the official launch in November 2005. The site grew rapidly, and in July 2006 the company announced that more than 65,000 new videos were being uploaded every day, and that the site was receiving 100 million video views per day.[14] According to data published by market research company comScore, YouTube is the dominant provider of online video in the United States, with a market share of around 43 percent and more than 14 billion videos viewed in May 2010.[15] YouTube says that over 48 hours of new videos are uploaded to the site every minute, and that around three quarters of the material comes from outside the US.[16][17] It is estimated that in 2007 YouTube consumed as much bandwidth as the entire Internet in 2000.[18] Alexa ranks YouTube as the third most visited website on the Internet, behind Google and Facebook.[19]
The choice of the name www.youtube.com led to problems for a similarly named website, www.utube.com. The owner of the site, Universal Tube & Rollform Equipment, filed a lawsuit against YouTube in November 2006 after being overloaded on a regular basis by people looking for YouTube. Universal Tube has since changed the name of its website to www.utubeonline.com.[20][21] In October 2006, Google Inc. announced that it had acquired YouTube for $1.65 billion in Google stock, and the deal was finalized on November 13, 2006.[22] Google does not provide detailed figures for YouTube's running costs, and YouTube's revenues in 2007 were noted as "not material" in a regulatory filing.[23] In June 2008, a Forbes magazine article projected the 2008 revenue at $200 million, noting progress in advertising sales.[24]
In November 2008, YouTube reached an agreement with MGM, Lions Gate Entertainment, and CBS, allowing the companies to post full-length films and television episodes on the site, accompanied by advertisements in a section for US viewers called "Shows". The move was intended to create competition with websites such as Hulu, which features material from NBC, Fox, and Disney.[25][26] In November 2009, YouTube launched a version of "Shows" available to UK viewers, offering around 4,000 full-length shows from more than 60 partners.[27] In January 2010, YouTube introduced an online film rentals service,[28] which is currently available only to users in the US, Canada and the UK.[29][30] The service offers over 6,000 films.[31]
YouTube's current headquarters in San Bruno, CaliforniaIn March 2010, YouTube began free streaming of certain content, including 60 cricket matches of the Indian Premier League. According to YouTube, this was the first worldwide free online broadcast of a major sporting event.[32]
On March 31, 2010, the YouTube website launched a new design, with the aim of simplifying the interface and increasing the time users spend on the site. Google product manager Shiva Rajaraman commented: "We really felt like we needed to step back and remove the clutter."[33] In May 2010, it was reported that YouTube was serving more than two billion videos a day, which it described as "nearly double the prime-time audience of all three major US television networks combined".[34] In May 2011, YouTube reported in its company blog that the site was receiving more than three billion views per day.[16]
In October 2010, Hurley announced that he would be stepping down as chief executive officer of YouTube to take an advisory role, and that Salar Kamangar would take over as head of the company.[35]
In April 2011, James Zern, a YouTube software engineer, revealed that 30 percent of videos accounted for 99 percent of views on the site.[36]
In November 2011, the Google+ social networking site was integrated directly with YouTube and the Chrome web browser, allowing YouTube videos to be viewed from within the Google+ interface.[37] In December 2011, YouTube launched a new version of the site interface, with the video channels displayed in a central column on the home page, similar to the news feeds of social networking sites.[38] At the same time, a new version of the YouTube logo was introduced with a darker shade of red, the first change in design since October 2006.[39]
Naming your song on Youtube and then listening to and watching your favourite artist perform is truly a great feat of modern technology.
It has given me hours of pleasure.
Friday 9 December 2011
Too many things
Though I have many things to be thankful for, I haven't been thankful for them.Shame on me!What things are they then? Just off the top of my head-my computer, screen, mouse, electricity, plugs, Facebook, google, email,bedroom, rug, polished floor, Bob Dylan,jeans, socks, wool pullover, shirt, watch, tablets, table, photographs,good friends,a beautiful wife ( of course she is number one on my main list of God's gifts!) book cases, CD's.DVD's. Well that's 25 things and I have not even tried. Forgive me for taking them for granted!
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