Magnetic diffusivity - Revision history

en>RockMagnetist: Removed expert-subject tag - no reason given for tag

2014-10-28T16:43:30Z

Removed expert-subject tag - no reason given for tag

← Older revision		Revision as of 18:43, 28 October 2014
Line 1:		Line 1:
	~~{\| align="right"~~
	~~\| __TOC__~~
	\|}

	The '''Heliocentric Julian Date (HJD)''' is the [[Julian Date]] (JD) corrected for differences in the [[Earth]]'s position with respect to the [[Sun]]. When timing events that occur beyond the [[Solar System]], due to the finite [[speed of light]], the time the event is observed depends on the changing position of the observer in the Solar System. Before multiple observations can be combined, they must be reduced to a common, fixed, reference location. This correction also depends on the direction to the object or event being timed.

	~~== Magnitude and limitations ==~~		e - Shop Word - Press is a excellent cart for your on the web shopping organization. Affilo - Theme is the guaranteed mixing of wordpress theme that Mark Ling use for his internet marketing career. This CMS has great flexibility to adapt various extensions and add-ons. Dead links are listed out simply because it will negatively have an influence on the website's search engine rating. The top 4 reasons to use Business Word - Press Themes for a business website are:. <br><br>Most Word - Press web developers can provide quality CMS website solutions and they price their services at reasonable rates. WPTouch is among the more well known Word - Press smartphone plugins which is currently in use by thousands of users. With the free Word - Press blog, you have the liberty to come up with your own personalized domain name. By purchasing Word - Press weblogs you can acquire your very own domain title and have total command of your web site. But in case you want some theme or plugin in sync with your business needs, it is advisable that you must seek some professional help. <br><br>The least difficult and very best way to do this is by acquiring a Word - Press site. Word - Press has different exciting features including a plug-in architecture with a templating system. If Gandhi was empowered with a blogging system, every event in his life would have been minutely documented so that it could be recounted to the future generations. Provide the best and updated information to the web searchers and make use of these wonderful free themes and create beautiful websites. If you beloved this article and you simply would like to get more info regarding [http://ad4.fr/wordpress_backup_6615704 wordpress backup plugin] nicely visit our web-site. Customization of web layout is easy due to the availability of huge selection of templates. <br><br>If all else fails, please leave a comment on this post with the issue(s) you're having and help will be on the way. The SEOPressor Word - Press SEO Plugin works by analysing each page and post against your chosen keyword (or keyword phrase) and giving a score, with instructions on how to improve it. Exacting subjects in reality must be accumulated in head ahead of planning on your high quality theme. Word - Press is the most popular open source content management system (CMS) in the world today. See a product, take a picture, and it gives you an Amazon price for that product, or related products. <br><br>There is no denying that Magento is an ideal platform for building ecommerce websites, as it comes with an astounding number of options that can help your online business do extremely well. Mahatma Gandhi is known as one of the most prominent personalities and symbols of peace, non-violence and freedom. It's not a secret that a lion share of activity on the internet is takes place on the Facebook. ) Remote Login: With the process of PSD to Wordpress conversion comes the advantage of flexibility. Definitely when you wake up from the slumber, you can be sure that you will be lagging behind and getting on track would be a tall order.

	~~The correction~~ is ~~zero (HJD = JD)~~ for ~~objects at~~ the ~~poles~~ of ~~the [[ecliptic]]~~. ~~Elsewhere,~~ it ~~is approximately~~ an ~~annual sine curve, and the highest amplitude occurs~~ on the ~~ecliptic~~. The ~~maximum correction corresponds~~ to ~~the time in which light travels the distance from the Sun to the Earth, i.e. ±8.3 min (500 s, 0.0058 days).~~

	~~JD and HJD~~ are ~~defined independent of the [[time standard]]~~. ~~Rather, JD~~ can ~~be expressed as e~~.~~g. [[Universal Time\|UTC, UT1]], [[Terrestrial Time\|TT]] or [[International Atomic Time\|TAI]]. The differences between these time standards are of~~ the ~~order of a minute, so that for minute accuracy of timings the standard used has to be stated. The HJD correction involves the heliocentric position of the Earth,~~ which is ~~expressed~~ in TT. ~~While~~ the ~~practical choice may be UTC~~, the ~~natural choice is TT~~.

	~~Since the Sun itself orbits around the [[Barycentric coordinates (astronomy)\|barycentre]]~~ of ~~the Solar System~~, ~~the HJD correction~~ is ~~not actually to a fixed reference~~. The ~~difference between correction to the heliocentre~~ and to ~~the barycentre~~ is ~~up to ±4 s~~. ~~For second accuracy~~, ~~the [[Barycentric Julian Date]] (BJD) should~~ be ~~calculated instead of~~ the ~~HJD~~.

	~~The common formulation of~~ the ~~HJD correction assumes that~~ the ~~object is at infinite distance, certainly beyond the Solar System~~. ~~The resulting error for [[Edgeworth-Kuiper Belt]] objects~~ would ~~be 5 s, and for objects in the~~ [~~[main asteroid belt~~]~~] it would be 100 s~~. ~~In this calculation, the [[Moon]] – which~~ is ~~closer than the Sun – can be wrongly placed on~~ the ~~far side~~ of ~~the Sun, resulting in an error~~ of ~~about 15 min~~.

	~~== Calculation ==~~

	~~In terms of the vector~~ <~~math~~>~~\vec{r}~~<~~/math~~> ~~from the heliocentre to the observer~~, the ~~unit vector <math>\hat{n}</math> from the observer toward the object or event, and the speed of light <math>c</math>:~~

	~~<math>HJD = JD + \frac{\vec{r} \cdot \hat{n}}{c} </math>~~

	~~When the [[scalar product]] is expressed in terms of the [[right ascension]] <math>\alpha</math> and [[declination]] <math>\delta</math> of the Sun~~ (~~index <math>\odot</math>~~) and of the ~~extrasolar object this becomes:~~

	~~<math>HJD = JD~~ - ~~\frac{r}{c} \cdot [sin~~(~~\delta~~) ~~\cdot sin(\delta_{\odot}) + cos(\delta) \cdot cos(\delta_{\odot}) \cdot cos(\alpha - \alpha_{\odot})]</math>~~

	~~where <math>r</math> is the distance between Sun~~ and ~~observer~~. ~~The same equation can~~ be ~~used with any [[astronomical coordinate system]]~~. ~~In [[Ecliptic coordinate~~ system~~\|ecliptic coordinates]]~~ the ~~Sun is at latitude zero~~, so that

	<~~math~~>~~HJD = JD - \frac{r}{c} \cdot cos(\beta) \cdot cos(\lambda - \lambda_{\odot})~~<~~/math~~>

	~~== See also ==~~

	* [[Barycentric Julian Date]]
	* [[Time standard]]

	~~== References ==~~

	* J. Eastman, R. ~~Siverd~~, ~~B. Scott Gaudi (2010). "Achieving better than one~~-~~minute accuracy in the Heliocentric~~ and ~~Barycentric Julian Dates"~~. '~~'Publications~~ of the ~~Astronomical Society of~~ the ~~Pacific'', submitted. Online at [http://arxiv.org/abs/1005.4415 http://arxiv.org/abs/1005.4415], retrieved 2010-05-27~~.
	* A. Hirshfeld, R.W. Sinnott (1997). ''Sky catalogue 2000.0, volume 2, double stars, variable stars and nonstellar objects'', p. xvii. Sky Publishing Corporation (ISBN 0-933346-38-7) and Cambridge University Press (ISBN 0-521-27721-3).

	~~== External links ==~~

	* [http:~~//astroutils~~.~~astronomy.ohio-state.edu/time/ http://astroutils.astronomy.ohio-state.edu/time/]: Online converter~~ from ~~UTC to BJD<sub>TDB</sub>~~, ~~BJD<sub>TDB</sub> to UTC, or HJD (UTC or TT) to BJD<sub>TDB</sub>~~.

	~~[[Category:Time scales]]~~
	~~[[Category:Time in astronomy]]~~

en>Addbot: Bot: Migrating 2 interwiki links, now provided by Wikidata on d:q6731548

2013-03-19T16:13:26Z

Bot: Migrating 2 interwiki links, now provided by Wikidata on d:q6731548

← Older revision		Revision as of 18:13, 19 March 2013
Line 1:		Line 1:
			{\| align="right"
			\| __TOC__
			\|}

			The '''Heliocentric Julian Date (HJD)''' is the [[Julian Date]] (JD) corrected for differences in the [[Earth]]'s position with respect to the [[Sun]]. When timing events that occur beyond the [[Solar System]], due to the finite [[speed of light]], the time the event is observed depends on the changing position of the observer in the Solar System. Before multiple observations can be combined, they must be reduced to a common, fixed, reference location. This correction also depends on the direction to the object or event being timed.

	~~e - Shop Word - Press~~ is ~~a excellent cart~~ for ~~your on~~ the ~~web shopping organization~~. ~~Online available for hiring are most qualified~~, ~~well knowledgeable~~ and ~~talented Wordpress developer India~~ from ~~offshore Wordpress development services company~~. ~~This CMS has great flexibility to adapt various extensions and add-ons~~. ~~If you need a special plugin for your website~~ , ~~there~~ are ~~thousands~~ of ~~plugins that~~ can be ~~used to meet those needs~~. ~~In the most current edition you can customize your retailer layout and display hues and fonts similar to your site~~ or ~~blog~~. ~~<br><br>Any business enterprise that is certainly worth its name should really shell out~~ a ~~good deal in making sure~~ that ~~they have~~ the ~~most effective website that provides related info~~ to ~~its prospect~~. ~~Best~~ of ~~all~~, ~~you can still have all~~ the ~~functionality that you desire when you use~~ the ~~Word - Press platform~~. ~~This may possibly also permit it currently being seriously straightforward to modify~~ the ~~hues within your Ad - Sense code so~~ the ~~ads blend nicely with~~ the ~~many term broad internet word wide web web page in case you can come~~ to ~~your conclusion~~ to ~~run~~ the ~~adverts~~. E-~~commerce websites are meant to~~ be ~~buzzed with fresh contents, graphical enhancements~~, and ~~functionalities~~. ~~If you loved~~ this ~~article therefore you would like to get more info concerning~~ [~~http://247url.info/wordpress_dropbox_backup_702237 wordpress dropbox backup~~] ~~please visit our web-site. Moreover, many Word - Press themes need to be purchased and designing your own WP site~~ can be ~~boring~~. <br><br>~~You can down load it here at this link: and utilize your FTP software program to upload it to your Word - Press Plugin folder. But if you are not willing to choose cost~~ to the ~~detriment of quality~~, ~~originality and higher returns~~, ~~then go for a self-hosted wordpress blog~~ and ~~increase~~ the ~~presence~~ of ~~your business~~ in this ~~new digital age~~. ~~Setting Up Your Business Online Using Free Wordpress Websites. You or your web designer~~ can ~~customize it as per your specific needs~~. ~~There are plenty of tables~~ that ~~are attached to this particular database.~~ <br><br>~~Digg Digg Social Sharing~~ - ~~This plugin that is accountable for~~ the ~~floating social icon located at~~ the ~~left aspect corner~~ of ~~just about every submit~~. * ~~Robust CRM to control and connect with your subscribers~~. ~~A higher percentage of women are marrying at older ages~~,~~many are delaying childbearing until their careers are established~~, ~~the divorce rate is high~~ and ~~many couples remarry~~ and ~~desire their own children~~. ~~IVF ,fertility,infertility expert,surrogacy specialist in India at Rotundaivf~~. ~~Look for experience~~: ~~When you are searching for a Word~~ - ~~Press developer you should always look at their experience level~~. <br><br>~~Internet is not only the source for information~~, ~~it is also one of the source for passive income. Visit our website~~ to ~~learn more about how you can benefit. This allows updates to be sent anyone who wants them via an RSS reader~~ or ~~directly~~ to ~~their email~~. ~~Extra investment~~ in ~~Drupal must be bypassed as value for money is what Drupal provides. The 2010 voting took place from July 7 through August 31, 2010.~~		== Magnitude and limitations ==

			The correction is zero (HJD = JD) for objects at the poles of the [[ecliptic]]. Elsewhere, it is approximately an annual sine curve, and the highest amplitude occurs on the ecliptic. The maximum correction corresponds to the time in which light travels the distance from the Sun to the Earth, i.e. ±8.3 min (500 s, 0.0058 days).

			JD and HJD are defined independent of the [[time standard]]. Rather, JD can be expressed as e.g. [[Universal Time\|UTC, UT1]], [[Terrestrial Time\|TT]] or [[International Atomic Time\|TAI]]. The differences between these time standards are of the order of a minute, so that for minute accuracy of timings the standard used has to be stated. The HJD correction involves the heliocentric position of the Earth, which is expressed in TT. While the practical choice may be UTC, the natural choice is TT.

			Since the Sun itself orbits around the [[Barycentric coordinates (astronomy)\|barycentre]] of the Solar System, the HJD correction is not actually to a fixed reference. The difference between correction to the heliocentre and to the barycentre is up to ±4 s. For second accuracy, the [[Barycentric Julian Date]] (BJD) should be calculated instead of the HJD.

			The common formulation of the HJD correction assumes that the object is at infinite distance, certainly beyond the Solar System. The resulting error for [[Edgeworth-Kuiper Belt]] objects would be 5 s, and for objects in the [[main asteroid belt]] it would be 100 s. In this calculation, the [[Moon]] – which is closer than the Sun – can be wrongly placed on the far side of the Sun, resulting in an error of about 15 min.

			== Calculation ==

			In terms of the vector <math>\vec{r}</math> from the heliocentre to the observer, the unit vector <math>\hat{n}</math> from the observer toward the object or event, and the speed of light <math>c</math>:

			<math>HJD = JD + \frac{\vec{r} \cdot \hat{n}}{c} </math>

			When the [[scalar product]] is expressed in terms of the [[right ascension]] <math>\alpha</math> and [[declination]] <math>\delta</math> of the Sun (index <math>\odot</math>) and of the extrasolar object this becomes:

			<math>HJD = JD - \frac{r}{c} \cdot [sin(\delta) \cdot sin(\delta_{\odot}) + cos(\delta) \cdot cos(\delta_{\odot}) \cdot cos(\alpha - \alpha_{\odot})]</math>

			where <math>r</math> is the distance between Sun and observer. The same equation can be used with any [[astronomical coordinate system]]. In [[Ecliptic coordinate system\|ecliptic coordinates]] the Sun is at latitude zero, so that

			<math>HJD = JD - \frac{r}{c} \cdot cos(\beta) \cdot cos(\lambda - \lambda_{\odot})</math>

			== See also ==

			* [[Barycentric Julian Date]]
			* [[Time standard]]

			== References ==

			* J. Eastman, R. Siverd, B. Scott Gaudi (2010). "Achieving better than one-minute accuracy in the Heliocentric and Barycentric Julian Dates". ''Publications of the Astronomical Society of the Pacific'', submitted. Online at [http://arxiv.org/abs/1005.4415 http://arxiv.org/abs/1005.4415], retrieved 2010-05-27.
			* A. Hirshfeld, R.W. Sinnott (1997). ''Sky catalogue 2000.0, volume 2, double stars, variable stars and nonstellar objects'', p. xvii. Sky Publishing Corporation (ISBN 0-933346-38-7) and Cambridge University Press (ISBN 0-521-27721-3).

			== External links ==

			* [http://astroutils.astronomy.ohio-state.edu/time/ http://astroutils.astronomy.ohio-state.edu/time/]: Online converter from UTC to BJD<sub>TDB</sub>, BJD<sub>TDB</sub> to UTC, or HJD (UTC or TT) to BJD<sub>TDB</sub>.

			[[Category:Time scales]]
			[[Category:Time in astronomy]]

en>Ankid: Rewrote conductivity to be more general - previous formulation was confusing when dealing with liquid metal magnetohydrodynamics

2011-12-07T12:01:57Z

Rewrote conductivity to be more general - previous formulation was confusing when dealing with liquid metal magnetohydrodynamics

New page

e - Shop Word - Press is a excellent cart for your on the web shopping organization. Online available for hiring are most qualified, well knowledgeable and talented Wordpress developer India from offshore Wordpress development services company. This CMS has great flexibility to adapt various extensions and add-ons. If you need a special plugin for your website , there are thousands of plugins that can be used to meet those needs. In the most current edition you can customize your retailer layout and display hues and fonts similar to your site or blog. Any business enterprise that is certainly worth its name should really shell out a good deal in making sure that they have the most effective website that provides related info to its prospect. Best of all, you can still have all the functionality that you desire when you use the Word - Press platform. This may possibly also permit it currently being seriously straightforward to modify the hues within your Ad - Sense code so the ads blend nicely with the many term broad internet word wide web web page in case you can come to your conclusion to run the adverts. E-commerce websites are meant to be buzzed with fresh contents, graphical enhancements, and functionalities. If you loved this article therefore you would like to get more info concerning [http://247url.info/wordpress_dropbox_backup_702237 wordpress dropbox backup] please visit our web-site. Moreover, many Word - Press themes need to be purchased and designing your own WP site can be boring. You can down load it here at this link: and utilize your FTP software program to upload it to your Word - Press Plugin folder. But if you are not willing to choose cost to the detriment of quality, originality and higher returns, then go for a self-hosted wordpress blog and increase the presence of your business in this new digital age. Setting Up Your Business Online Using Free Wordpress Websites. You or your web designer can customize it as per your specific needs. There are plenty of tables that are attached to this particular database. Digg Digg Social Sharing - This plugin that is accountable for the floating social icon located at the left aspect corner of just about every submit. * Robust CRM to control and connect with your subscribers. A higher percentage of women are marrying at older ages,many are delaying childbearing until their careers are established, the divorce rate is high and many couples remarry and desire their own children. IVF ,fertility,infertility expert,surrogacy specialist in India at Rotundaivf. Look for experience: When you are searching for a Word - Press developer you should always look at their experience level. Internet is not only the source for information, it is also one of the source for passive income. Visit our website to learn more about how you can benefit. This allows updates to be sent anyone who wants them via an RSS reader or directly to their email. Extra investment in Drupal must be bypassed as value for money is what Drupal provides. The 2010 voting took place from July 7 through August 31, 2010.