Linear complex structure - Revision history

en>Cesium 133: fixed the ambig link...

2014-11-21T10:07:49Z

fixed the ambig link...

← Older revision		Revision as of 12:07, 21 November 2014
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	~~The [[American Petroleum Institute]] gravity, or~~ '''''API gravity''''', is a measure of how heavy or light a [[petroleum]] liquid is compared to water. If its API gravity is greater than 10, it is lighter and floats on water; if less than 10, it is heavier and sinks. API gravity is thus an inverse measure of the relative density of a petroleum liquid and the density of water, but it is used to compare the relative densities of [[List of crude oil products\|petroleum liquids]]. For example, if one petroleum liquid floats on another and is therefore less dense, it has a greater API gravity. Although mathematically, API gravity has no units (see the formula below), it is nevertheless referred to as being in "degrees". API gravity is gradated in degrees on a [[#Direct Measurement of API gravity (~~Hydrometer method~~)~~\|hydrometer instrument]]. The API scale was designed so that most values would fall between 10 and 70 API gravity degrees.~~		I'm Mercedes (29) from Zenon Park, Canada. <br>I'm learning French literature at a local college and I'm just about to graduate.<br>I have a part time job in a college.<br><br>my page ... [http://Wheretoshopmilan.com/?page_id=2%FFsac+%C3%A0+main+celine%FFnofollow%FFcheap+nike+air+max+sale%FFnofollow how to get free fifa 15 coins]

	~~==History of development==~~
	The U.S. [[National Bureau of Standards]] in 1916 accepted the [[Baumé scale]], developed in France in 1768, as the U.S. standard for measuring the [[specific gravity]] of liquids less dense than [[Density of water\|water]]. Investigation by the U.S. National Academy of Sciences found major errors in [[salinity]] and temperature controls that had caused serious variations in published values. Hydrometers in the U.S. had been manufactured and distributed widely with a modulus of 141.5 instead of the Baumé scale modulus of 140. The scale was so firmly established that by 1921 the remedy implemented by the [[American Petroleum Institute]] was to create the API Gravity scale, recognizing the scale that was actually being used.

	~~==API gravity formulas==~~
	~~The formula to obtain API gravity of [[petroleum]] liquids,~~ from ~~[[specific gravity]] (SG)~~, ~~is:~~

	~~:<math>\text{API gravity} = \frac{141.5}{\text{SG}} - 131~~.5<~~/math~~>

	~~Conversely, the specific gravity of [[petroleum]] liquids can be derived from the API gravity value as~~

	~~:<math>\text{SG~~ at~~}~60^\circ\text{F} = \frac{141.5}{\text{API gravity} + 131.5}</math>~~

	~~Thus,~~ a ~~heavy oil with a specific gravity of 1.0 (i.e., with the same density as pure water at 60°F) would have an API gravity of:~~

	~~:<math>\frac{141.5}{1.0} - 131.5 = 10.0^\circ\text{API}</math>~~

	~~==Using API gravity~~ to ~~calculate barrels of crude oil per metric ton==~~
	~~In the oil industry, quantities of crude oil are often measured in metric tons~~. ~~One can calculate the approximate number of barrels per metric ton for a given crude oil based on its API gravity:~~

	:<~~math~~>~~\text{barrels of crude oil per metric ton} = 1\div\bigg[\frac{141.5}{\text{API gravity}+131.5} \times 0.159\bigg]</math>~~

	~~So, for example,~~ a ~~metric ton of [[West Texas Intermediate]] (39.6° API) would contain about 7.6 barrels.~~

	~~==Measurement of API gravity from its density==~~

	~~To derive the API gravity from the [[density]], the density is first measured using either the [[hydrometer]], detailed~~ in ~~[[ASTM]] D1298 or with the [[oscillating U-tube]] method detailed in ASTM D4052.~~
	Density adjustments at different temperatures, corrections for soda-lime glass expansion and contraction and [[meniscus]] corrections for opaque oils are detailed in the [[Petroleum Measurement Tables]], details of usage specified in ASTM D1250.
	~~The specific gravity is then calculated from the formula below and the API gravity calculated from the first formula above~~.

	:<~~math~~>~~\mbox{SG oil} = \frac{\rho_\text{oil}}{\rho_{\text{H}_2\text{O}}}~~<~~/math~~>

	~~==Direct Measurement of API gravity (Hydrometer method)==~~

	~~There are advantages to field testing and on-board conversion of measured volumes to volume correction.~~
	~~This method is detailed in ASTM D287.~~

	~~==Classifications or grades==~~
	Generally speaking, oil with an API gravity between 40 and 45 commands the highest prices. Above 45 degrees the molecular chains become shorter and less valuable to refineries.<ref>{{cite web\|title=Comments on Crude Oil Gravity Adjustments\|url=http://dnr.louisiana.gov/sec/execdiv/techasmt/oil_gas/crude_oil_gravity/comments_1989.htm\|publisher=Louisiana Department of Natural Resources\|accessdate=6 January 2014\|archiveurl=http://web.archive.org/web/20070118001025/http://dnr.louisiana.gov/sec/execdiv/techasmt/oil_gas/crude_oil_gravity/comments_1989.htm\|archivedate=18 January 2007}}</ref>

	~~[[Crude oil]] is classified as light, medium or heavy, according to its measured API gravity.~~

	* [[Light crude oil]] is defined as having an API gravity higher than 31.1 °API (less than 870 kg/m<sup>3</sup>)
	* Medium oil is defined as having an API gravity between 22.3 °API and 31.1 °API (870 to 920 kg/m<sup>3</sup>)
	* [[Heavy crude oil]] is defined as having an API gravity below 22.3 °API (920 to 1000 kg/m<sup>3</sup>)
	* Extra heavy oil is defined with API gravity below 10.0 °API (greater than 1000 kg/m<sup>3</sup>)

	Not all parties use the same grading.<ref>Crude oil grades, Crudemonitor.ca, web PDF file: [http://www.crudemonitor.ca/quickfacts/misc/grades.pdf CMonitor-Gr-PDF]</ref> The [[United States Geological Survey]] uses slightly different definitions.<ref>USGS FS2006-3133_508, web PDF file: [http://pubs.usgs.gov/fs/2006/3133/pdf/FS2006-3133_508.pdf USGS-508-PDF]</ref>

	~~Crude oil with API gravity less than 10 °API is referred to as [[extra heavy oil]] or [[bitumen]]~~. ~~Bitumen derived from the [[oil sands]] deposits in the Alberta, Canada area has an API gravity of around 8 °API~~. It can be diluted with lighter hydrocarbons to produce [[diluted bitumen]], having an API gravity of lower than 22.3 API, or further "upgraded" to an API gravity of 31 °API to 33 °API as [[synthetic crude]].<ref>Canadian Centre for Energy Information. [http://~~www.centreforenergy~~.com/~~AboutEnergy/ONG/Oil/Overview.asp~~?~~page~~=2 ~~"What is crude oil?"]. Retrieved on: 2012-09-10.</ref>~~

	~~==See also==~~
	* [[Density]]
	* [[Specific gravity]]
	* [[Specific weight]]

	~~== References ==~~
	~~{{Reflist}}~~

	~~==External links==~~
	*[http://www.koehlerinstrument.com/products/hydrometer.html Link to ~~hydrometer]~~
	*[http://dnr.louisiana.gov/assets/docs/oilgas/productiondata/comments_1989_rev.pdf Comments on API gravity adjustment scale]
	*[http://www.globalsecurity.org/military/library/policy/army/fm/10-67-1/APPI.HTML Instructions for using a glass hydrometer measured in API gravity]
	*[http://www.sizes.com/units/hydrometer_api.htm API Degree history]

	~~[[Category:Units of density]]~~
	~~[[Category:Physical quantities]]~~
	~~[[Category:Petroleum geology]]~~
	~~[[Category:Petroleum production]~~]

79.40.192.152: /* Definition and properties */

2014-01-06T19:55:07Z

Definition and properties

← Older revision		Revision as of 21:55, 6 January 2014
Line 1:		Line 1:
	~~Im Efrain~~ and was ~~born~~ on ~~2 September 1977~~. ~~My hobbies~~ are ~~Petal collecting~~ and ~~pressing~~ and ~~Amateur radio~~.<br><br>my web ~~site~~ - [http://www.~~ptgxhzs~~.com/~~plus~~/~~guestbook~~.~~php fifa 15 coin Generator~~]		The [[American Petroleum Institute]] gravity, or '''''API gravity''''', is a measure of how heavy or light a [[petroleum]] liquid is compared to water. If its API gravity is greater than 10, it is lighter and floats on water; if less than 10, it is heavier and sinks. API gravity is thus an inverse measure of the relative density of a petroleum liquid and the density of water, but it is used to compare the relative densities of [[List of crude oil products\|petroleum liquids]]. For example, if one petroleum liquid floats on another and is therefore less dense, it has a greater API gravity. Although mathematically, API gravity has no units (see the formula below), it is nevertheless referred to as being in "degrees". API gravity is gradated in degrees on a [[#Direct Measurement of API gravity (Hydrometer method)\|hydrometer instrument]]. The API scale was designed so that most values would fall between 10 and 70 API gravity degrees.

			==History of development==
			The U.S. [[National Bureau of Standards]] in 1916 accepted the [[Baumé scale]], developed in France in 1768, as the U.S. standard for measuring the [[specific gravity]] of liquids less dense than [[Density of water\|water]]. Investigation by the U.S. National Academy of Sciences found major errors in [[salinity]] and temperature controls that had caused serious variations in published values. Hydrometers in the U.S. had been manufactured and distributed widely with a modulus of 141.5 instead of the Baumé scale modulus of 140. The scale was so firmly established that by 1921 the remedy implemented by the [[American Petroleum Institute]] was to create the API Gravity scale, recognizing the scale that was actually being used.

			==API gravity formulas==
			The formula to obtain API gravity of [[petroleum]] liquids, from [[specific gravity]] (SG), is:

			:<math>\text{API gravity} = \frac{141.5}{\text{SG}} - 131.5</math>

			Conversely, the specific gravity of [[petroleum]] liquids can be derived from the API gravity value as

			:<math>\text{SG at}~60^\circ\text{F} = \frac{141.5}{\text{API gravity} + 131.5}</math>

			Thus, a heavy oil with a specific gravity of 1.0 (i.e., with the same density as pure water at 60°F) would have an API gravity of:

			:<math>\frac{141.5}{1.0} - 131.5 = 10.0^\circ\text{API}</math>

			==Using API gravity to calculate barrels of crude oil per metric ton==
			In the oil industry, quantities of crude oil are often measured in metric tons. One can calculate the approximate number of barrels per metric ton for a given crude oil based on its API gravity:

			:<math>\text{barrels of crude oil per metric ton} = 1\div\bigg[\frac{141.5}{\text{API gravity}+131.5} \times 0.159\bigg]</math>

			So, for example, a metric ton of [[West Texas Intermediate]] (39.6° API) would contain about 7.6 barrels.

			==Measurement of API gravity from its density==

			To derive the API gravity from the [[density]], the density is first measured using either the [[hydrometer]], detailed in [[ASTM]] D1298 or with the [[oscillating U-tube]] method detailed in ASTM D4052.
			Density adjustments at different temperatures, corrections for soda-lime glass expansion and contraction and [[meniscus]] corrections for opaque oils are detailed in the [[Petroleum Measurement Tables]], details of usage specified in ASTM D1250.
			The specific gravity is then calculated from the formula below and the API gravity calculated from the first formula above.

			:<math>\mbox{SG oil} = \frac{\rho_\text{oil}}{\rho_{\text{H}_2\text{O}}}</math>

			==Direct Measurement of API gravity (Hydrometer method)==

			There are advantages to field testing and on-board conversion of measured volumes to volume correction.
			This method is detailed in ASTM D287.

			==Classifications or grades==
			Generally speaking, oil with an API gravity between 40 and 45 commands the highest prices. Above 45 degrees the molecular chains become shorter and less valuable to refineries.<ref>{{cite web\|title=Comments on Crude Oil Gravity Adjustments\|url=http://dnr.louisiana.gov/sec/execdiv/techasmt/oil_gas/crude_oil_gravity/comments_1989.htm\|publisher=Louisiana Department of Natural Resources\|accessdate=6 January 2014\|archiveurl=http://web.archive.org/web/20070118001025/http://dnr.louisiana.gov/sec/execdiv/techasmt/oil_gas/crude_oil_gravity/comments_1989.htm\|archivedate=18 January 2007}}</ref>

			[[Crude oil]] is classified as light, medium or heavy, according to its measured API gravity.

			* [[Light crude oil]] is defined as having an API gravity higher than 31.1 °API (less than 870 kg/m<sup>3</sup>)
			* Medium oil is defined as having an API gravity between 22.3 °API and 31.1 °API (870 to 920 kg/m<sup>3</sup>)
			* [[Heavy crude oil]] is defined as having an API gravity below 22.3 °API (920 to 1000 kg/m<sup>3</sup>)
			* Extra heavy oil is defined with API gravity below 10.0 °API (greater than 1000 kg/m<sup>3</sup>)

			Not all parties use the same grading.<ref>Crude oil grades, Crudemonitor.ca, web PDF file: [http://www.crudemonitor.ca/quickfacts/misc/grades.pdf CMonitor-Gr-PDF]</ref> The [[United States Geological Survey]] uses slightly different definitions.<ref>USGS FS2006-3133_508, web PDF file: [http://pubs.usgs.gov/fs/2006/3133/pdf/FS2006-3133_508.pdf USGS-508-PDF]</ref>

			Crude oil with API gravity less than 10 °API is referred to as [[extra heavy oil]] or [[bitumen]]. Bitumen derived from the [[oil sands]] deposits in the Alberta, Canada area has an API gravity of around 8 °API. It can be diluted with lighter hydrocarbons to produce [[diluted bitumen]], having an API gravity of lower than 22.3 API, or further "upgraded" to an API gravity of 31 °API to 33 °API as [[synthetic crude]].<ref>Canadian Centre for Energy Information. [http://www.centreforenergy.com/AboutEnergy/ONG/Oil/Overview.asp?page=2 "What is crude oil?"]. Retrieved on: 2012-09-10.</ref>

			==See also==
			* [[Density]]
			* [[Specific gravity]]
			* [[Specific weight]]

			== References ==
			{{Reflist}}

			==External links==
			*[http://www.koehlerinstrument.com/products/hydrometer.html Link to hydrometer]
			*[http://dnr.louisiana.gov/assets/docs/oilgas/productiondata/comments_1989_rev.pdf Comments on API gravity adjustment scale]
			*[http://www.globalsecurity.org/military/library/policy/army/fm/10-67-1/APPI.HTML Instructions for using a glass hydrometer measured in API gravity]
			*[http://www.sizes.com/units/hydrometer_api.htm API Degree history]

			[[Category:Units of density]]
			[[Category:Physical quantities]]
			[[Category:Petroleum geology]]
			[[Category:Petroleum production]]

en>Brad7777: removed Category:Linear algebra; added Category:Structures on manifolds using HotCat

2012-02-02T18:16:17Z

removed Category:Linear algebra; added Category:Structures on manifolds using HotCat

New page

Im Efrain and was born on 2 September 1977. My hobbies are Petal collecting and pressing and Amateur radio.<br><br>my web site - [http://www.ptgxhzs.com/plus/guestbook.php fifa 15 coin Generator]