Dujiangyan and Cryogenics: Difference between pages

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:''Cryogenics is often used incorrectly to refer to [[cryonics]], cryopreserving humans or animals.''
{{For2|the adjacent city|[[Dujiangyan City]]}}
:''For the band, see [[Cryogenic (Band)]].''


{{Unreferenced|date=December 2007}}
{{Infobox World Heritage Site
| Coordinates = {{coord|31|0|6.012|N|103|36|19.008|E}}
| WHS = [[Mount Qingcheng]] and the Dujiangyan Irrigation System
| Image = [[Image:Dujiang Weir.jpg|260px|Dujiangyan Irrigation System]]
| State Party = [[Image:Flag of the People's Republic of China.svg|22px]] [[People's Republic of China|China]]
| Type = Cultural
| Criteria = ii, iv, vi
| ID = 1001
| Region = [[List of World Heritage Sites in Asia and Australasia|Asia-Pacific]]
| Year = 2000
| Session = 24th
| Link = http://whc.unesco.org/en/list/1001
}}


In [[physics]] or [[engineering]], '''cryogenics''' is the study of the production of very low [[temperatures]] (below –150 °C, –238 °F or 123 K) and the behavior of materials at those temperatures. Rather than the familiar temperature scales of [[Fahrenheit]] and [[Celsius]], cryogenicists use the [[Kelvin]] (and formerly [[Rankine scale|Rankine]]) scales.
{{Contains Chinese text}}


== Definitions and distinctions ==
'''Dujiangyan''' ({{zh-stp|s=都江堰|t=都江堰|p=Dūjiāngyàn}}) is an [[irrigation]] infra-structure built in 256 BC during the [[Warring States Period]] of [[China]] by the Kingdom of [[Qin (state)|Qin]]. It is located in the [[Min River (Sichuan)|Min River]] (岷江, Mínjiāng) in [[Sichuan]] Province, [[PR China]], near the capital [[Chengdu]] (成都, Chéngdu). It is still in use today and still irrigates over 5,300 square kilometers of land in the region.<ref name="zhangKan">{{cite book |title= World Heritage in China |last=Zhang |first=Kan |authorlink= |coauthors=Hu Changshu |year=2006 |publisher=The Press of South China University of Technology |location=Guangzhou |isbn=7-5623-2390-9 |pages=95-103}}</ref>


The terms ''cryogenics'', ''cryobiology'' and ''cryonics'' are frequently confused. Other new terms with the prefix ''cryo-'' have also been introduced.
==History==
===Planning===
During the [[Warring States]] period, around 2,300 years ago, the people who lived along the banks of the [[Min River (Sichuan)|Min River]] were plagued by annual flooding. [[Qin (state)|Qin]] governor [[Li Bing]] (李冰，Lǐ Bīng) investigated the problem and discovered that the river was swelled by the fast flowing spring melt-water from the local mountains that burst the banks when it reached the slow moving and heavily silted stretch below.<ref name="tctIntro1">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Dujiangyan Irrigation System | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = More than 2,000 years ago, Li Bing (c.250-200 BC) served as a local governor of Shu State. At that time, the Mingjiang River flowed fast down from mountains. As it ran across the Chengdu Plain, it frequently flooded the Chengdu agricultural area, and local farmers suffered much from the water disaster. Li Bing and his son designed this water control system and organized thousands of local people to construct the project.}}</ref>


; Cryogenics: The branches of physics and engineering that involve the study of very low temperatures, how to produce them, and how materials behave at those temperatures.
The most obvious solution would have been to build a [[dam]] but Li Bing had also been charged with keeping the waterway open for military vessels to supply troops on the frontier,<ref name="anuTaming1">{{cite web | url = http://www.chinaheritagenewsletter.org/features.php?searchterm=001_water.inc&issue=001 | title = Taming the Floodwaters | accessdate = April 22 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = China Heritage Project | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = The Australian National University | pages = | doi = | archiveurl = | archivedate = | quote = Li Bing was commissioned to conduct an extensive hydraulic survey to regulate the unpredictable course of the swiftly flowing spring-thaw waters of the Min River that regularly flooded areas and settlements on the plains around Chengdu, and simultaneously ensure that the Min River had a fairway flow through Chengdu, facilitating navigation by military vessels that could service Qin's logistical supply lines.}}</ref> so instead he preposed to construct an artificial levee to redirect a portion of the river's flow and then to cut a channel through Mount Yulei to discharge the excess water upon the dry [[Chengdu Plain]] beyond.<ref name="anuTaming2">{{cite web | url = http://www.chinaheritagenewsletter.org/features.php?searchterm=001_water.inc&issue=001 | title = Taming the Floodwaters | accessdate = April 22 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = China Heritage Project | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = The Australian National University | pages = | doi = | archiveurl = | archivedate = | quote = By 270 BCE he had drawn up plans to mitigate the Min River's floodwaters for year-round irrigation on the Chengdu Plain and navigability to Chengdu. The original plan called for the construction of weirs or levees to harness the Min River at Dujiangyan, where the hills meet the Chengdu Plain, and of a diversion channel to irrigate the plain that would cut straight through the natural barrier posed by Mount Jian.}}</ref>


; [[Cryobiology]]: The branch of [[biology]] involving the study of the effects of low temperatures on [[organism]]s (most often for the purpose of achieving [[cryopreservation]]).
===Construction===
Li Bing received 100,000 taels of silver for the project from [[King Zhao of Qin]] and set to work with a team said to number tens of thousands. The levee was constructed from long sausage-shaped basket of woven [[bamboo]] filled with stones known as Zhulong<ref name="disZhulong1">{{cite news | first = | last = | authorlink = | author = | coauthors = | title = Zhulong | url = | format = | work = | publisher = Dujiangyan Irrigation System Museum | pages = | page = | date = | accessdate = | quote = It is also called Zhuluo, Zhulou, etc. which is a long sausage-shaped basket of woven bamboo filled with stones used to protect the riverbed or served as a dam. While the Dujiangyan Irrigation Project under the guidance of Li Bing, Zhulong was widely used. It was simple and cheap but effective and has been passé down from generation to generation. Even today it is still widely adopted in flood control.}}</ref> held in place by wooden tripods known as Macha.<ref name="disMacha1">{{cite news | first = | last = | authorlink = | author = | coauthors = | title = Zhulong | url = | format = | work = | publisher = Dujiangyan Irrigation System Museum | pages = | page = | date = | accessdate = | quote = They are wood tripods used to support a temporary dam to cut off a river, control flood or regulate water, etc. They are one kind of flexible convenient and effective engineering facilities.}}</ref> The massive construction took four years to complete.<ref name="anuTaming3">{{cite web | url = http://www.chinaheritagenewsletter.org/features.php?searchterm=001_water.inc&issue=001 | title = Taming the Floodwaters | accessdate = April 22 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = China Heritage Project | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = The Australian National University | pages = | doi = | archiveurl = | archivedate = | quote = In 268 BCE, Li Bing is said to have personally led ten of thousands of workers in the initial stage of construction on the Min River banks. The workers made bamboo cages and threw cages of rocks into the middle of the river. It took them four years to complete a water-diversion levee resembling a fish's mouth. When the water reaches Yuzui, the 'fish's mouth,' it is naturally diverted into the inner and outer flows. The inner flow is the diversion channel that leads to Chengdu.}}</ref>


; [[Cryonics]]: The emerging [[medical technology]] of [[cryopreservation|cryopreserving]] humans and animals with the intention of future revival. Researchers in the field seek to apply the results of many [[science]]s, including cryobiology, cryogenics, [[rheology]], [[emergency medicine]], etc.
Cutting the channel proved to be a far greater problem as the tools available to him at the time, prior to the invention of [[gunpowder]], were unable to penetrate the hard rock of the mountain so he used a combination of fire and water to heat and cool the rock until they cracked and could be removed.<ref name="anuTaming4">{{cite web | url = http://www.chinaheritagenewsletter.org/features.php?searchterm=001_water.inc&issue=001 | title = Taming the Floodwaters | accessdate = April 22 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = China Heritage Project | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = The Australian National University | pages = | doi = | archiveurl = | archivedate = | quote = Prior to the invention of gunpowder, manual labourers using only drill rods and stone hammers would have taken 30 years to cut through the mountain. Qin military planners required more immediate results, so Li Bing proposed using the expeditious and simple technology of using controlled blazes to scorch the rocks and then dousing them with cold water. The seemingly limitless forest resources of the region at that time – evidence of which is provided by the Shu kingdom period tree trunk coffins recently unearthed in downtown Chengdu – made such an option possible. King Zhao of Qin allocated 100,000 taels of silver for the project.}}</ref> After eight years of work a 20 m wide channel had been gouged through the mountain.<ref name="anuTaming5">{{cite web | url = http://www.chinaheritagenewsletter.org/features.php?searchterm=001_water.inc&issue=001 | title = Taming the Floodwaters | accessdate = April 22 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = China Heritage Project | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = The Australian National University | pages = | doi = | archiveurl = | archivedate = | quote = It took a further eight years to cut through the mountain, and the 20 m wide culvert allows the water to flow into the Chengdu Plain. The key part of the project was the diversion gate called Baopingkou that resembles the neck of a bottle, and through this passage, the waters of the Min River could irrigate the Chengdu Plain in perpetuo. In 256 BCE, after 14 years of arduous labour, the Dujiangyan project was completed. That, at least is one received historical account, but it is undeniable that for more than two millennia this irrigation project has been in use on the Chengdu Plain.}}</ref>


; [[Cryoelectronics]]: The field of research regarding [[superconductivity]] at low temperatures.
===Legacy===
[[Image:Dujiangyan Irrigation System.jpg|260px|thumb|right|Dujiangyan]]
After the system was finished, no more floods occurred. The irrigation made [[Sichuan]] the most productive agricultural place in [[China]]. [[Li Bing]] was loved so much that he became a god to the people there. On the east side of Dujiangyan, people built a shrine in remembrance of [[Li Bing]].


; [[Cryotronics]]: The practical application of cryoelectronics.
Li Bing’s construction is also credited with giving the people of the region a laid-back attitude to life,<ref name="laTimes1">{{cite web | url = http://www.latimes.com/news/nationworld/columnone/la-fi-chinaparty8feb08,1,7457737.story?page=2&coll=la-headlines-columnone | title = People's Party Animals | accessdate = April 22 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = Lee | first = Don | authorlink = | coauthors = | date = 8 | year = 2006 | month = February | format = | work = | publisher = Los Angeles Times | pages = | doi = | archiveurl = | archivedate = | quote = [Luo Xinben, a professor at Southwest University for Nationalities] and other scholars say Chengdu's laid-back culture was spawned by its 2-millennium-old irrigation system.}}</ref> by eliminating disaster and insuring a regular and bountiful harvest it has left them with plenty of free-time.<ref name="laTimes2">{{cite web | url = http://www.latimes.com/news/nationworld/columnone/la-fi-chinaparty8feb08,1,7457737.story?page=2&coll=la-headlines-columnone | title = People's Party Animals | accessdate = April 22 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = Lee | first = Don | authorlink = | coauthors = | date = 8 | year = 2006 | month = February | format = | work = | publisher = Los Angeles Times | pages = | doi = | archiveurl = | archivedate = | quote = [Tan Jihe, a researcher at the Sichuan Provincial Academy of Social Sciences] says Du Jiang Yan, and Chengdu's fertile soil and moist air, made it easy to plant rice, corn, potatoes and a rich assortment of citrus and other fruits, giving farmers not only good harvests but also plenty of time for leisure.}}</ref>


== Etymology ==
Today, Dujiangyan has become a major tourist attraction. It is also the admiration of scientists around the world, because it has one ingenious feature. Unlike contemporary [[dams]] where the water is blocked with a huge wall, Dujiangyan still lets water go through naturally. Modern [[dams]] do not let fish go through very well, since each dam is a wall and the water levels are different. In 2000, Dujiangyan became a [[UNESCO World Heritage Site]].


The word ''cryogenics'' means "the production of freezing cold"; however the term is used today as a [[synonym]] for the low-temperature state. It is not well-defined at what point on the temperature scale [[refrigeration]] ends and cryogenics begins. The workers at the [[National Institute of Standards and Technology]] at [[Boulder, Colorado]] have chosen to consider the field of cryogenics as that involving temperatures below –180 [[Celsius|°C]] (93.15 [[Kelvin|K]]). This is a logical dividing line, since the normal [[boiling point]]s of the so-called permanent [[gases]] (such as [[helium]], [[hydrogen]], [[neon]], [[nitrogen]], [[oxygen]], and normal [[Earth's atmosphere|air]]) lie below -180 °C while the [[Freon]] refrigerants, [[hydrogen sulfide]], and other common refrigerants have boiling points above -180 °C.
===2008 Sichuan earthquake===
{{main|2008 Sichuan earthquake}}
On [[May 12]], [[2008]] a massive earthquake centred on the Dujiangyan area struck. Initial reports indicate that the Yuzui Levee was cracked but not severely damaged<ref name="reliefWeb">{{citenews|url=http://www.reliefweb.int/rw/rwb.nsf/db900SID/KHII-7EMA3N?OpenDocument&RSS20=03 |title=China quake weakens Sichuan dams, cuts off river|author=Hornby, Lucy|publisher=Relief Web|accessdate=2008-05-14}}</ref> while the Two Kings Temple was levelled.<ref name="shanghaiDaily">{{citenews|url=http://www.shanghaidaily.com/sp/article/2008/200805/20080514/article_359528.htm |title=Most historical relics survive Sichuan quake|author= Chen, Lydia|publisher=Shanghai Daily|accessdate=2008-05-14}}</ref>


== Industrial application ==
==Engineering Constructions==
{{see|Timeline of low-temperature technology}}
[[Image:Yuzui1.jpg|260px|thumb|right|Fish Mouth Levee]]
[[Liquid air|Liquefied gases]], such as [[liquid nitrogen]] and liquid helium, are used in many cryogenic applications. Liquid nitrogen is the most commonly used element in cryogenics and is legally purchasable around the world. Liquid helium is also commonly used and allows for the lowest attainable temperatures to be reached.
===Irrigation Head===
Li Bing’s Irrigation System consists of three main constructions that work in harmony with one another to ensure against flooding and keep the fields well supplied with water.


These liquids are held in either special containers known as [[Dewar flask]]s, which are generally about six feet tall (1.8 m) and three feet (91.5 cm) in diameter, or giant tanks in larger commercial operations. Dewar flasks are named after their inventor, [[James Dewar]], the man who first liquefied [[hydrogen]]. Museums typically display smaller [[vacuum flask]]s fitted in a protective casing.
'''Yuzui''' or '''Fish Mouth Levee''', named for its conical head that is said to resemble the mouth of a fish, is the key part of Li Bing’s construction. It is an artificial [[levee]] that divides the water into inner and outer streams.<ref name="tctFishMouth1">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-2.html | title = At The Fish Mouth Water-Dividing Dam | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = The Fish Mouth Water-Dividing Dam is built in the middle of the river. It is the main part of Dujiangyan Irrigation system. The Fish mouth functions to divide the river into an inner canal and an outer canal. Long ago, when Li Ping worked as the local governor of the Shu State, he found the old river canal was too narrow to hold much water, which often overflowed the banks and caused disastrous floods. Based on natural geographic conditions, Li Bing organized the people to build a man-made dam. The whole dam looks like a fish, and the front dam has a circular cone shaped like a fish mouth.}}</ref> The inner stream carries approximately 40%, rising to 60% during flood, of the river’s flow into the irrigation system whilst that outer stream drains away the rest, flushing out much of the silt and sediment.<ref name="tctFishMouth2">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-2.html | title = At The Fish Mouth Water-Dividing Dam | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = It is the dam that diverts water into the outer canal and the inner canal. The inner water canal functions as the main stream for irrigation purposes; the outer river is mainly used to drain excessive water and sand. During flood seasons the inner canal holds 60 percent of the water in the river, and 40 percent of the water flows into the outer river. It is vice versa in dry seasons. About 80 percent of the silt is carried away along the outer river.}}</ref>


Cryogenic transfer pumps are the pumps used on [[LNG pier]]s to transfer [[Liquefied Natural Gas]] from [[LNG carrier|LNG Carriers]] to [[Storage tank|LNG storage tanks]].
'''Feishayan''' or '''Flying Sand Weir''' has a 200 m-wide opening that connects the inner and outer streams.<ref name="tctFlyingSandFence1">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-2.html | title = At the Flying Sand Fence | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = The water flows along the inner canal towards the Bottle-Neck Channel. On the way it passes the Flying Sand Fence, which has a 200-meter-wide opening from south to north. The Fence joins the inner and outer canals. The fence functions to control the flow of water and discharge excess into the outer canal from the inner canal.}}</ref> This ensures against flooding by allowing the natural swirling flow of the water to drain out excess water from the inner to the outer stream. A modern reinforced [[concrete]] [[weir]] has replaced Li Bing’s original weighted bamboo baskets.<ref name="tctFlyingSandFence2">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-2.html | title = At the Flying Sand Fence | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = During the dry seasons the fence doesn't work much, but when floods occur, the river rushes forward along the inner canal. As it approaches the fence, the river begins to turn fast, and soon many whirlpools are formed. The whirlpools change quickly, swee-ping away sand and pebbles, and throwing them into the outer canal. During the flood seasons, this spillway transports 80 percent of the sediments into the outer river, and at the same time excessive water flows over the Flying Sands Fence into the outer river. In ancient times, there was no cement in use. Instead, huge bamboo cages were used as the fence. They were filled with stones and pebbles. However, at present, a reinforced concrete weir has replaced the ancient fence.}}</ref>
'''Baopingkou''' or '''Bottle-Neck Channel''', which Li Bing gouged through the mountain, is the final part of the system. The channel distributes the water to the farmlands to the west, whilst the narrow entrance, that gives it its name, works as a check gate, creating the whirlpool flow that carries away the excess water over Flying Sand Fence, to ensure against flooding.<ref name="tctBottleNeckChannel1">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-2.html | title = At the Bottle-Neck Channel | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = The inner canal leads to the Bottleneck Channel, which is the entrance of the extensive irrigation system. A trunk canal cuts the mountain into two parts. The small part was later called Li Dui, which means an isolated hill. Chengdu looks like a large bottle, and the trunk canal between the mountain and the hill takes the shape of a bottleneck. During the flood seasons, the water will not overflow into the trunk canal. Instead, it flows in whirlpools into the outer canal. The trunk canal works as a check gate to safeguard the Chengdu Plain.}}</ref>


===Anlan Suspension Bridge===
=== Cryogenic processing ===
Anlan or Couple's Bridge spans the full width of the river connecting the artificial island to both banks and is known as one of the ''Five Ancient Bridges of China''. Li Bing’s original Zhupu Bridge only spanned the inner stream connecting the levee to the foot of Mount Yulei. This was replaced in the [[Song Dynasty]] by Pingshi Bridge which burned down during the wars that marked the end of the [[Ming Dynasty]].<ref name="disAnlan1">{{cite news | first = | last = | authorlink = | author = | coauthors = | title = Anlan Bridge | url = | format = | work = | publisher = Dujiangyan Irrigation System Museum | pages = | page = | date = | accessdate = | quote = The bridge is 261 meters long across both the inner river and the outer river. It was called Zhupu Bridge in ancient times and was rebuiltin the Song Dynasty and called Pinshi Bridge. In the late Ming Dynasty(1368-1644), it was burned in a war. In the 8th year of Jiaqing Reign(1803 A.D.) of the Qing Dynasty, He Xiande ,a native, and his wife proposed rebuilding it and as a result the people on both banks could cross the raging waves in safety, hence it was called Anlan Bridge and also called Couple Bridge at that time.}}</ref>


The field of cryogenics advanced during World War II when scientists found that metals frozen to low temperatures showed more resistance to wear. Based on this theory of [[cryogenic hardening]], the commercial [[cryogenic processor|cryogenic processing]] industry was founded in 1966 by [[Ed Busch]]. With a background in the [[heat treatment|heat treating]] industry, Busch founded a company in [[Detroit, Michigan|Detroit]] called [[CryoTech]] in 1966. Though [[CryoTech]] later merged with [[300 Below]] to create the largest and oldest commercial cryogenics company in the world, they originally experimented with the possibility of increasing the life of metal tools to anywhere between 200%-400% of the original life expectancy using [[cryogenic tempering]] instead of heat treating. This evolved in the late 1990s into the treatment of other parts (that did more than just increase the life of a product) such as amplifier valves (improved sound quality), baseball bats (greater sweet spot), golf clubs (greater sweet spot), racing engines (greater performance under stress), firearms (less warping after continuous shooting), knives, razor blades, brake rotors and even pantyhose. The theory was based on how heat-treating metal works (the temperatures are lowered to room temperature from a high degree causing certain strength increases in the molecular structure to occur) and supposed that continuing the descent would allow for further strength increases. Using liquid nitrogen, CryoTech formulated the first early version of the [[cryogenic processor]]. Unfortunately for the newly-born industry, the results were unstable, as components sometimes experienced [[thermal shock]] when they were cooled too fast. Some components in early tests even shattered because of the ultra-low temperatures. In the late twentieth century, the field improved significantly with the rise of applied research, which coupled microprocessor based industrial controls to the [[cryogenic processor]] in order to create more stable results.
In 1803 during the [[Qing Dynasty]] a local man named He Xiande and his wife proposed the construction of a replacement, made of wooden plates and bamboo handrails, to span both streams and this was this was nick-named Couple’s Bridge in their honour. This was replaced in 1970 by a modern bridge of reinforced concrete and steel chains that is now opened to visitors.<ref name="tctAnlan1">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Anlan Suspension Bridge | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = Anlan Suspension Bridge is one of the five ancient bridges in China. The total length is 320 m. Its ancient name was called the Rope Suspension Bridge or the Bamboo and Cane Suspension Bridge. Unfortunately, a fire caused by war towards the end of the Ming dynasty destroyed the original bridge. In 1803, a new bridge was built. It was made with local bamboo rope chains, and the bridge bottom floor was replaced with wooden plates. The old bridge lasted until the 1970s when it was replaced by a steel chains bridge.}}</ref>


Cryogens, like liquid [[nitrogen]], are further used for specialty chilling and freezing applications. Some chemical reactions, like those used to produce the active ingredients for the popular [[statin]] drugs, must occur at low temperatures of approximately -100 °C. Special cryogenic [[chemical reactor]]s are used to remove reaction heat and provide a low temperature environment. The freezing of foods and biotechnology products, like [[vaccine]]s, requires nitrogen in blast freezing or immersion freezing systems. Certain soft or elastic materials become hard and [[brittleness|brittle]] at very low temperatures, which makes cryogenic [[mill (grinding)|milling]] (grinding) an option for some materials that cannot easily be milled at higher temperatures.
==Temple Sites==
===Two Kings Temple===
[[Image:Erwang Temple.JPG|thumb|The Erwang Temple at Dujiangyan]]
Erwang or Two Kings Temple is located on the bank of the river at the foot of Mount Yulei. The original Wangdi Temple built in memory of an ancient [[Shu (state)|Shu]] king was relocated and so locals renamed the temple here in honour of Li Bing and his legendary son whom they had posthumously promoted to kings.<ref name="tctErwang1">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Two Kings' Temple at DuJianYan | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = Erwang (Two King's) Temple was built to commemorate Li Bing and his son. Erwang means two kings. Originally, the temple was called Wangdi Temple in memory of Duyu, the king of the ancient Shu. Later Wangdi Temple was relocated in Pixian county during the Southern and Northern Dynasties. So local people renamed the temple as Chongdemiao in order to express the respect of Li Bing and his son. Chongde means the worship of virtue or reverence. During the Song Dynasty the temple was called Wangmiao, which means the king's temple. Down to the Qing Dynasty it was called Erwang Temple. People offered Li Bing and his son the posthumous title of Wang (king).}}</ref>


=== Fuels ===
The 10,072m² [[Qing Dynasty]] wooden complex conforms to the traditional standard of temple design except that it does not follow a north-south axis.<ref name="tctErwang2">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Two Kings' Temple at DuJianYan | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = The temple complex occupies an area of 10,072 square meters. the ancient timber buildings remain similar in design and style to other ancient Chinese architecture. The broad roof, perfect decoration, strict size and traditional use of color meet in harmony with the mountaintop environment. However, the temple buildings are not placed based on the concept of the north-south axis.}}</ref> The main hall, which contains a modern statue of Li Bing,<ref name="tctErwang5">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Two Kings' Temple at DuJianYan | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = The main hall is devoted to Li Bing himself. The statue is newly molded. The old statue was a larger-than-life painted statue, and the figure looked like a wise scholar looking at the rushing river below. The newly molded figure has a silk map in his hand, and his eyes are bright with wisdom. It appears as if he is thinking about the blueprint of the project.}}</ref> opens up onto a courtyard facing an opera stage. On Li Bing's traditional birthday, 24th day of the 7th month of the lunar calendar,<ref name="tctErwang6">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Two Kings' Temple at DuJianYan | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = According to Folk tale, July 24 of the Chinese Lunar Calendar is Li Ping's birthday. On that day many local people visit the temple where they prostrate themselves before the image of Li Ping and his son and burn incense to honor them. At the same time, the beatings of drums and gongs resound to the sky as incense smoke curls upwards.}}</ref> local operas were performed for the public,<ref name="tctErwang7">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Two Kings' Temple at DuJianYan | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = Li Bing's hall is a compound. The hall faces an opera stage across the courtyard below, surrounded by other buildings. On July 24 of the Chinese Lunar Calendar during the Ming and Qing dynasties local operas would be performed on the stage. Many people would gather in the courtyard and watch the performance. It is said that the actors offered the performance mainly for Li Bing as a tribute for his great contribution to local people.}}</ref> and on [[Tomb Sweeping Day]] a Water Throwing Festival is held.


Another use of cryogenics is [[cryogenic fuel]]s. Cryogenic fuels, mainly [[liquid hydrogen]], have been used as rocket fuels. ([[Oxygen]] is used as an [[Redox|oxidizer]] of hydrogen, but oxygen is not, strictly speaking, a fuel.) For example, [[NASA]]'s workhorse [[space shuttle]] uses cryogenic hydrogen fuel as its primary means of getting into [[orbit]], as did all of the rockets built for the [[Soviet space program]] by [[Sergei Korolev]]. (This was a bone of contention between him and rival engine designer [[Valentin Glushko]], who felt that cryogenic fuels were impractical for large-scale rockets such as the ill-fated [[N-1 rocket]] spacecraft.)
The rear hall contains a modern statue of the god [[Erlang Shen]] who was allegedly Li Bing’s son,<ref name="tctErwang3">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Two Kings' Temple at DuJianYan | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = The rear hall is devoted to Li Bing's son. His son's statue is newly molded. The figure stands firmly with a tool in his hands as if he was ready to level down mountains. Behind the statue is the Minjiang River, which serves as the background. Li Bing's son had a name called Erlang.}}</ref> but historic records fail to confirm this and it is possible that he was invented by locals to give their hero a descendent to maintain his family heritage.<ref name="tctErwang4">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Two Kings' Temple at DuJianYan | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = Erlang is a popular legendary figure in Chinese folk literature. In the folk stories, he has a close relationship with Li Bing. It should be pointed out that no recorded historical evidence could be found to show Erlang was Li Bing's son. In Chinese feudal society, it would be a great problem if a family had no offspring. So in ancient times, local people regarded Erlang as Li Bing's son. They sincerely wished that Li Bing would have a son so that Li's family tree would continue.}}</ref> Guanlantin Pavilion stands above the complex and is inscribed with wise words from Li Bing such as, ''When the river flows in zigzags, cut a straight channel; when the riverbed is wide and shallow, dig it deeper.''<ref name="tctErwan8">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-1.html | title = Two Kings' Temple at DuJianYan | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = There is a delicate pavilion called Guanlantin. Carved characters are on both sides of stonewalls. These are quotations of how to manage the Dujiangyan Irrigation System. One of the famous inscriptions engraved on the wall is an eight-character quotation from Li Ping. It says: When the river flows in zigzags, cut a straight channel; when the riverbed is wide and shallow, dig it deeper.}}</ref>


Russian aircraft manufacturer [[Tupolev]] is currently researching a version of its popular design [[Tu-154]] with a cryogenic fuel system, known as the [[Tu-155]]. The plane uses a fuel referred to as [[liquefied natural gas]] or LNG, and made its first flight in 1989.
===Dragon-Taming Temple===
[[Image:32302450 DuJiangYan007.jpg|thumb|]]
Fulonguan or Dragon-Taming Temple in Liudi Park was founded in the third century in honour of [[Fan Changsheng]], the [[Jin Dynasty]] founder of [[Daoism|Tianshi Daoism]]. Following Li Bing’s death a hall was established here in his honour and the temple was renamed to commemorate the dragon fighting legends that surrounded him.<ref name="tctFulonguan1">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-2.html | title = On the way to Fulonguan (The Dragon-Taming Temple) | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = The Dragon-Taming Temple is located in the beautiful Lidui Park, which is close to the city. It was built in the 3rd century. Originally, it was devoted to Fan Changsheng, the founder of Tianshi Dao, one Daoist sect in the Jin Dynasty (265-420). During the Five Dynasties and Ten States, Li Bing was conferred the posthumous title called Da'anwang, and his hall was set up here in honor of him. A popular legend during the Song Dynasty was that Erwang, Li Bing's son, had subdued an evil dragon here. So the temple was renamed as the Dragon-Taming Temple accordingly.}}</ref>


== Production ==
It is here that [[Erlang Shen]], the legendary son of [[Li Bing]], is said to have chained the dragon that he and his 7 friends had captured in an ambush at the River God Temple when it came to collect a human sacrifice. This action is said to have protected the region from floods ever since.<ref name="chengManchao">{{cite book |title= The Origin of Chinese Deities |last=Cheng Manchao |first= |authorlink= |coauthors= |year=1995 |publisher=Foreign Languages Press |location=Beijing |isbn=7-119-00030-6 |pages=170-180}}</ref>
Cryogenic cooling of devices and material is usually achieved via the use of [[liquid nitrogen]], [[liquid helium]], or a cryocompressor (which uses high pressure helium lines).


== Detectors ==
During the [[East Han Dynasty]] a statue of Li Bing was place in the river to monitor the water flow, with the level rising above his shoulders to indicate flood and falling beneath his calves to indicate drought. Recovered from the river in 1974 and placed on display in the main hall, this is the oldest known stone statue of a human in China.<ref name="tctFulonguan2">{{cite web | url = http://www.travelchinatour.com/sichuan-china/dujiangyan-irrigation-system-2.html | title = On the way to Fulonguan (The Dragon-Taming Temple) | accessdate = April 20 | accessdaymonth = | accessmonthday = | accessyear = 2008 | author = | last = | first = | authorlink = | coauthors = | date = | year = | month = | format = | work = | publisher = travelchinatour.com | pages = | doi = | archiveurl = | archivedate = | quote = In 1974, a stone statue of Li Bing was unearthed from the river base. The carved figure looks graceful. Now it is placed in the middle of the main hall. It is 2.9 m in height and 4.5 tons in weight. Based on archeological studies, the statue was carved in 168 during the East Han Dynasty.}}</ref><ref name="justinWintle">{{cite book |title= The Rough Guide History of China |last=Wintle |first=Justin |authorlink= |coauthors= |year=2002 |publisher=Rough Guides Ltd. |location=London |isbn=1-85828-764-2 |pages=78}}</ref>


Cryogenic temperatures, usually well below 77 K (-196 °C) are required to operate [[cryogenic detectors]].
==See also==
{{Commonscat|Dujiangyan}}
* [[Li Bing]]
* [[Erlang Shen]]
* [[Turfan water system]]
* [[Grand Canal (China)|Grand Canal of China]]
* [[2008 Sichuan earthquake]]


==References==
== See also ==
* [[1 E2 K]]
{{reflist|2}}
* [[Absolute zero]]
* [[Coldest temperature recorded on Earth]]
* [[Cryocoolers]]
* [[Cryogenic processor]]
* [[Cryogenic tempering]]
* [[Cryobiology]]
* [[Cryonics]]
* [[Cryopreservation]]
* [[Ex-situ conservation]]
* [[Frozen zoo]]
* [[List of publications in physics#Cryogenics|Important publications in cryogenics]]
* [[Liquid nitrogen#Molecular nitrogen .28gas and liquid.29|Liquid nitrogen]]
* [[Quantum hydrodynamics]], [[Superfluidity]] or [[Superconductivity]]
* [[Superconductivity]]
* [[Superconducting RF]]
* [[Timeline of low-temperature technology]]
* [[Wildlife conservation]]
* [[Apollo 13]]
* [[Cryogenic deflashing]]
* [[Cryogenic deburring]]
* [[Deep Cryogenic Treatment]]
* [[Futurama]]


== External links ==
{{World Heritage Sites in China}}
* [http://www.magnet.fsu.edu/education/tutorials/magnetacademy/cryogenics/ Cryogenics for English Majors: An introduction for non-scientists] National High Magnetic Field Laboratory
*[http://www.cryogenicsociety.org/ Cryogenic Society of America, Inc. (CSA)]
*[http://www.lancs.ac.uk/depts/physics/research/condmatt/ult/index.html Lancaster University, Ultra Low Temperature Physics] - ULT research group homepage
* [http://www.tupolev.ru/English/Show.asp?SectionID=82 Tupolev's pages regarding Cryogenic airliners]
* [http://www.iifiir.org/en/doc/1052.pdf Cryogenics, Key to Advanced Science and Technology]
* [http://doc.cern.ch/archive/electronic/cern/preprints/at/at-2007-001.pdf An Introduction to Cryogenics]


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[[Category:World Heritage Sites in China]]
[[Category:National parks of China]]
[[Category:Chinese architectural history]]
[[Category:Sichuan]]
[[Category:Irrigation projects]]
[[Category:Irrigation in China]]


[[Category:Cryogenics| ]]
[[cs:Tuťiangjenský zavlažovací systém]]
[[Category:Cooling technology]]
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[[de:Dujiangyan-Bewässerungssystem]]
[[ar:علم التبريد]]
[[es:Sistema de irrigación de Dujiangyan]]
[[de:Kryotechnik]]
[[fr:Système d'irrigation de Dujiangyan]]
[[el:Κρυογονική]]
[[ko:두장옌]]
[[es:Criogenia]]
[[it:Sistema di irrigazione del Dujiangyan]]
[[fa:سرماشناسی]]
[[ja:都江堰 (水利施設)]]
[[fr:Cryogénie]]
[[pt:Sistema de Irrigação de Dujiangyan]]
[[is:Lághitafræði]]
[[ru:Дуцзянъянь]]
[[it:Criogenia]]
[[fi:Dujiangyanin kastelujärjestelmä]]
[[vi:Đô Giang Yển]]
[[lt:Kriogenika]]
[[zh:都江堰]]
[[nl:Cryogeen]]
[[ja:低温物理学]]
[[pl:Kriogenika]]
[[pt:Criogenia]]
[[ru:Криогеника]]
[[sv:Kryoteknik]]
[[zh:低温物理学]]

Revision as of 01:52, 11 October 2008

Cryogenics is often used incorrectly to refer to cryonics, cryopreserving humans or animals.
For the band, see Cryogenic (Band).

In physics or engineering, cryogenics is the study of the production of very low temperatures (below –150 °C, –238 °F or 123 K) and the behavior of materials at those temperatures. Rather than the familiar temperature scales of Fahrenheit and Celsius, cryogenicists use the Kelvin (and formerly Rankine) scales.

Definitions and distinctions

The terms cryogenics, cryobiology and cryonics are frequently confused. Other new terms with the prefix cryo- have also been introduced.

Cryogenics
The branches of physics and engineering that involve the study of very low temperatures, how to produce them, and how materials behave at those temperatures.
Cryobiology
The branch of biology involving the study of the effects of low temperatures on organisms (most often for the purpose of achieving cryopreservation).
Cryonics
The emerging medical technology of cryopreserving humans and animals with the intention of future revival. Researchers in the field seek to apply the results of many sciences, including cryobiology, cryogenics, rheology, emergency medicine, etc.
Cryoelectronics
The field of research regarding superconductivity at low temperatures.
Cryotronics
The practical application of cryoelectronics.

Etymology

The word cryogenics means "the production of freezing cold"; however the term is used today as a synonym for the low-temperature state. It is not well-defined at what point on the temperature scale refrigeration ends and cryogenics begins. The workers at the National Institute of Standards and Technology at Boulder, Colorado have chosen to consider the field of cryogenics as that involving temperatures below –180 °C (93.15 K). This is a logical dividing line, since the normal boiling points of the so-called permanent gases (such as helium, hydrogen, neon, nitrogen, oxygen, and normal air) lie below -180 °C while the Freon refrigerants, hydrogen sulfide, and other common refrigerants have boiling points above -180 °C.

Industrial application

Further information: Timeline of low-temperature technology

Liquefied gases, such as liquid nitrogen and liquid helium, are used in many cryogenic applications. Liquid nitrogen is the most commonly used element in cryogenics and is legally purchasable around the world. Liquid helium is also commonly used and allows for the lowest attainable temperatures to be reached.

These liquids are held in either special containers known as Dewar flasks, which are generally about six feet tall (1.8 m) and three feet (91.5 cm) in diameter, or giant tanks in larger commercial operations. Dewar flasks are named after their inventor, James Dewar, the man who first liquefied hydrogen. Museums typically display smaller vacuum flasks fitted in a protective casing.

Cryogenic transfer pumps are the pumps used on LNG piers to transfer Liquefied Natural Gas from LNG Carriers to LNG storage tanks.

Cryogenic processing

The field of cryogenics advanced during World War II when scientists found that metals frozen to low temperatures showed more resistance to wear. Based on this theory of cryogenic hardening, the commercial cryogenic processing industry was founded in 1966 by Ed Busch. With a background in the heat treating industry, Busch founded a company in Detroit called CryoTech in 1966. Though CryoTech later merged with 300 Below to create the largest and oldest commercial cryogenics company in the world, they originally experimented with the possibility of increasing the life of metal tools to anywhere between 200%-400% of the original life expectancy using cryogenic tempering instead of heat treating. This evolved in the late 1990s into the treatment of other parts (that did more than just increase the life of a product) such as amplifier valves (improved sound quality), baseball bats (greater sweet spot), golf clubs (greater sweet spot), racing engines (greater performance under stress), firearms (less warping after continuous shooting), knives, razor blades, brake rotors and even pantyhose. The theory was based on how heat-treating metal works (the temperatures are lowered to room temperature from a high degree causing certain strength increases in the molecular structure to occur) and supposed that continuing the descent would allow for further strength increases. Using liquid nitrogen, CryoTech formulated the first early version of the cryogenic processor. Unfortunately for the newly-born industry, the results were unstable, as components sometimes experienced thermal shock when they were cooled too fast. Some components in early tests even shattered because of the ultra-low temperatures. In the late twentieth century, the field improved significantly with the rise of applied research, which coupled microprocessor based industrial controls to the cryogenic processor in order to create more stable results.

Cryogens, like liquid nitrogen, are further used for specialty chilling and freezing applications. Some chemical reactions, like those used to produce the active ingredients for the popular statin drugs, must occur at low temperatures of approximately -100 °C. Special cryogenic chemical reactors are used to remove reaction heat and provide a low temperature environment. The freezing of foods and biotechnology products, like vaccines, requires nitrogen in blast freezing or immersion freezing systems. Certain soft or elastic materials become hard and brittle at very low temperatures, which makes cryogenic milling (grinding) an option for some materials that cannot easily be milled at higher temperatures.

Fuels

Another use of cryogenics is cryogenic fuels. Cryogenic fuels, mainly liquid hydrogen, have been used as rocket fuels. (Oxygen is used as an oxidizer of hydrogen, but oxygen is not, strictly speaking, a fuel.) For example, NASA's workhorse space shuttle uses cryogenic hydrogen fuel as its primary means of getting into orbit, as did all of the rockets built for the Soviet space program by Sergei Korolev. (This was a bone of contention between him and rival engine designer Valentin Glushko, who felt that cryogenic fuels were impractical for large-scale rockets such as the ill-fated N-1 rocket spacecraft.)

Russian aircraft manufacturer Tupolev is currently researching a version of its popular design Tu-154 with a cryogenic fuel system, known as the Tu-155. The plane uses a fuel referred to as liquefied natural gas or LNG, and made its first flight in 1989.

Production

Cryogenic cooling of devices and material is usually achieved via the use of liquid nitrogen, liquid helium, or a cryocompressor (which uses high pressure helium lines).

Detectors

Cryogenic temperatures, usually well below 77 K (-196 °C) are required to operate cryogenic detectors.

See also

External links

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