en>JaconaFrere: Reverted 1 good faith edit by 115.117.131.253 using STiki

2015-01-08T21:46:46Z

Reverted 1 good faith edit by 115.117.131.253 using STiki

en>Oalp1003: /* Analog modulation methods */ corrected wrong preposition

2014-01-30T10:49:52Z

Analog modulation methods: corrected wrong preposition

← Older revision		Revision as of 12:49, 30 January 2014
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	It's that ~~time~~ of ~~year when functioning ahead~~ to ~~2009~~, to ~~our own goals~~ and ~~plans for your coming current year~~. ~~Most businesses will be doing planning for~~ that ~~coming year~~, and ~~individuals will be making New Year's resolutions straight~~.<br><br>~~I hereby offer several initial suggestions~~ and ~~I am sure Let me come develop many more~~, ~~but I needed to know what you~~, the ~~techlover, knows~~. ~~Perhaps together home furniture come i'll carry on with some basic framework~~ for ~~keeping our net presence intact~~ as ~~we navigate~~ the ~~treacherous online break over?~~<br><br><br><br>~~Blogging is~~ the ~~best way to create leads~~. ~~People post content to your internet site~~ that ~~has value to others you'll repeat leads~~. ~~Frequent blogging means search engine traffic also~~. ~~Blogging~~ is ~~among~~ the ~~finest ways~~ to ~~get cheap MLM leads~~.<br><br>~~Finally~~, ~~type~~ in ~~the words that you would use~~ to ~~look for a Reverse Mortgage provider in place on Google or yahoo~~. ~~Who comes up~~ first~~? What websites are showing on~~ the ~~first page~~ and are ~~you able~~ to ~~get for auction on those? If so~~, ~~go for it~~.<br><br>~~Learn~~ the ~~best way~~ to ~~promote using Social Media~~. ~~Simply posting links~~ to ~~enterprise website~~ is ~~not advertising -~~ it is ~~spam~~. ~~Providing content~~ to be a ~~reason~~ to ~~visit your website~~ is ~~alot more effective, additionally~~ also ~~allows consumers to feel~~ as ~~though you are interested in their personal wants~~ and ~~needs~~.<br><br>~~You purchase your way into links, but here we~~'~~re talking around~~ a ~~few free and easy ways~~. ~~This really is and natural way to develop links is through content~~. ~~When you begin a link~~-~~building campaign for your new website~~, ~~focus on attracting links that include value in your website visitors and best represent your most important keywords too~~. It is ~~invaluable to have visitors go to some site~~ and ~~share within~~ the.<br><br>~~Make it simpler for your prospects to produce a sale made. Lessen~~ the ~~chances~~ of ~~losing~~ a ~~procurement by this hassle-free for all your customers to buy~~ from ~~you have to~~. ~~I recommend~~ that ~~you incorporate ecommerce features upon website and merely ask for that information have to have when somebody is putting in an order.~~<br><br>~~When you loved this post~~ and ~~you want~~ to ~~receive more details regarding~~ [http://www.~~mavsocial~~.~~com~~/ ~~Social Media Digital Asset Management~~] ~~kindly visit our own web-site~~.		[[File:Melting icecubes.gif\|thumb\|Ice melting]]
			{{Redirect\|Molten\|the Japanese company\|Molten Corporation\|other uses\|Molton (disambiguation)\|and\|Moulton (disambiguation)}}

			'''Melting''', or '''fusion''', is a physical process that results in the [[phase transition]] of a substance from a [[solid]] to a [[liquid]]. The [[internal energy]] of a substance is increased, typically by the application of heat or pressure, resulting in a rise of its temperature to the [[melting point]], at which the ordering of ionic or molecular entities in the solid breaks down to a less ordered state and the solid liquefies. An object that has melted completely is ''molten''. Substances in the molten state generally have reduced viscosity with elevated temperature; an exception to this maxim is the element [[sulfur]], whose viscosity increases to a point due to [[polymerization]] and then decreases with higher temperatures in its molten state.<ref>C.Michael Hogan (2011) ''Sulfur'', Encyclopedia of Earth, eds. A.Jorgensen and C.J.Cleveland, National Council for Science and the environment, Washington DC</ref>

			Some organic compounds melt through [[mesophase]]s, states of partial order between solid and liquid.

			==Thermodynamics of melting==
			{{main\|Melting point}}

			When a substance melts and the solid and liquid phases are in an equilibrium, it maintains a constant temperature, the melting point. The energy used for melting is a [[latent heat]]. This characterizes the process of melting as a first-order phase transition.

			From a thermodynamics point of view, at the melting point the change in [[Gibbs free energy]] (<math>\Delta G</math>) of the material is zero, but the [[enthalpy]] (<math>H</math>) and the [[entropy]] (<math>S</math>) of the material are increasing (<math>\Delta H, \Delta S > 0</math>). Melting occurs when the Gibbs free energy of the liquid becomes lower than the solid for that material. The temperature at which this occurs is dependent on the ambient pressure.

			Low-temperature [[helium]] is the only known exception to the general rule.<ref>{{Citation \|last=Atkins \|first=Peter \|last2=Jones \|first2=Loretta \|year=2008 \|title=Chemical Principles: The Quest for Insight \|edition=4th \|publisher=W. H. Freeman and Company \|isbn=0-7167-7355-4 \|page=236}}</ref> [[Helium-3]] has a negative enthalpy of fusion at temperatures below 0.3 K. [[Helium-4]] also has a very slightly negative enthalpy of fusion below 0.8 K. This means that, at appropriate constant pressures, heat must be ''removed'' from these substances in order to melt them.<ref>{{Citation \|last=Ott \|first=J. Bevan \|last2=Boerio-Goates \|first2=Juliana \|year=2000 \|title=Chemical Thermodynamics: Advanced Applications \|publisher=Academic Press \|isbn=0-12-530985-6 \|pages=92–93}}</ref>

			==Melting criteria==

			Among the theoretical criteria for melting, the Lindemann <ref>F.A. Lindemann, Z. Phys. 11 (1910) 609–615.</ref> and Born <ref>M. Born, J. Chem. Phys. 7 (1939) 591–601.</ref> criteria are those most frequently used as a basis to analyse the melting conditions . The Lindemann criterion states that melting occurs because of vibrational instability, e.g. [[crystal]]s melt when the average amplitude of thermal vibrations of atoms is relatively high compared with interatomic distances, e.g. <''δu<sup>2</sup>''>1/2 > ''δ<sub>L</sub>R<sub>s</sub>'', where ''δu'' is the atomic displacement, the Lindemann parameter ''δ<sub>L</sub>'' ≈ 0.20...0.25 and ''R<sub>s</sub>'' is a half of the inter-atomic distance. The Lindemann melting criterion is supported by experimental data both for [[crystal]]line materials and for [[glass-liquid transition]]s in amorphous materials. The Born criterion is based on rigidity catastrophe caused by the vanishing elastic shear modulus, e.g. when the crystal no longer has sufficient rigidity to mechanically withstand load.

			==Supercooling==
			{{main\|Supercooling}}

			Under a standard set of conditions, the melting point of a substance is a characteristic property. The melting point is often equal to the [[melting point\|freezing point]]. However, under carefully created conditions, supercooling or superheating past the melting or freezing point can occur. [[properties of water\|Water]] on a very clean glass surface will often supercool several degrees below the freezing point without freezing. Fine emulsions of pure water have been cooled to −38 degrees Celsius without nucleation to form [[ice]].{{Citation needed\|date=April 2008}}. Nucleation occurs due to fluctuations in the properties of the material. If the material is kept still there is often nothing (such a physical vibration) to trigger this change, and supercooling (or superheating) may occur. Thermodynamically, the supercooled liquid is in the metastable state with respect to the crystalline phase, and it is likely to crystallize suddenly.

			==Melting of amorphous solids (glasses)==

			Glasses are amorphous solids (e.g. amorphous materials that are at temperatures below the glass transition temperature) which are usually fabricated when the viscous molten material cools very rapidly to below its glass transition temperature, without sufficient time for a regular crystal lattice to form. Whether a material is liquid or solid depends primarily on the connectivity between its elementary building blocks so that solids are characterised by a high degree of connectivity where as fluids occur at lower connectivity of the structural blocks. Melting of a solid material can also be considered as a percolation via broken connections between particles e.g. connecting bonds.<ref>S.Y. Park and D. Stroud, Phys. Rev. B 67, 212202 (2003).</ref> In this approach melting of an amorphous material occurs when the broken bonds form a percolation cluster with ''T<sub>g</sub>'' dependent on quasi-equilibrium thermodynamic parameters of bonds e.g. on enthalpy (''H<sub>d</sub>'') and entropy (''S<sub>d</sub>'') of formation of bonds in a given system at given conditions:<ref>M.I. Ojovan, W.E. Lee. J. Non-Cryst. Solids, 356, 2534–2540 (2010).</ref>

			:<math>T_g = \frac{H_d}{S_d+ R \ln(\frac{1-f_c}{f_c})},</math>

			where ''f<sub>c</sub>'' is the percolation threshold and ''R'' is the universal gas constant. Although ''H<sub>d</sub>'' and ''S<sub>d</sub>'' are not true equilibrium thermodynamic parameters and can depend on the cooling rate of a melt they can be found from available experimental data on [[viscosity of amorphous materials]].

			==Premelting (surface melting)==
			{{main\|Premelting}}

			Premelting (also: Surface melting) describes the fact that, even below its melting point <math>T_s</math>, quasi-liquid films can be observed on crystalline surfaces. The thickness of the film is temperature dependent. This effect is common for all crystalline materials. Premelting shows its effects in e.g. frost heave, the growth of snowflakes and, taking grain boundary interfaces into account, maybe even in the movement of glaciers.

			==Related concepts==
			{{Wiktionary\|melting}}

			In [[genetics]], melting [[DNA]] means to separate the double-stranded DNA into two single strands by heating or the use of chemical agents, cf. [[Polymerase chain reaction]].

			==See also==
			* [[List of elements]] providing melting points
			* [[Phase diagram]]
			* [[Zone melting]]

			==References==
			{{reflist}}

			==References and further reading==
			* [[Hagen Kleinert\|Kleinert, Hagen]]. ''Gauge Fields in Condensed Matter'', Vol. II, "[[Stress (physics)\|STRESSES]] AND [[Crystallographic defect\|DEFECTS]]; [[differential geometry\|Differential Geometry]], Crystal Melting", pp. 743–1456, World Scientific (Singapore, 1989); Paperback ISBN 9971-5-0210-0 '' (readable online [http://www.physik.fu-berlin.de/~kleinert/kleiner_reb1/contents2.html here])''
			* C.Michael Hogan. 2011. [http://www.eoearth.org/article/Sulfur?topic=49557 ''sulfur''. Encyclopedia of Earth, eds. A.Jorgensen and C.J.Cleveland, National Council for Science and the environment, Washington DC]

			{{Table of Phase Transitions}}

			[[Category:Phase transitions]]
			[[Category:Materials science]]

en>Calumet96: /* List of common digital modulation techniques */

2012-06-21T06:46:30Z

List of common digital modulation techniques

New page

It's that time of year when functioning ahead to 2009, to our own goals and plans for your coming current year. Most businesses will be doing planning for that coming year, and individuals will be making New Year's resolutions straight. I hereby offer several initial suggestions and I am sure Let me come develop many more, but I needed to know what you, the techlover, knows. Perhaps together home furniture come i'll carry on with some basic framework for keeping our net presence intact as we navigate the treacherous online break over? Blogging is the best way to create leads. People post content to your internet site that has value to others you'll repeat leads. Frequent blogging means search engine traffic also. Blogging is among the finest ways to get cheap MLM leads. Finally, type in the words that you would use to look for a Reverse Mortgage provider in place on Google or yahoo. Who comes up first? What websites are showing on the first page and are you able to get for auction on those? If so, go for it. Learn the best way to promote using Social Media. Simply posting links to enterprise website is not advertising - it is spam. Providing content to be a reason to visit your website is alot more effective, additionally also allows consumers to feel as though you are interested in their personal wants and needs. You purchase your way into links, but here we're talking around a few free and easy ways. This really is and natural way to develop links is through content. When you begin a link-building campaign for your new website, focus on attracting links that include value in your website visitors and best represent your most important keywords too. It is invaluable to have visitors go to some site and share within the. Make it simpler for your prospects to produce a sale made. Lessen the chances of losing a procurement by this hassle-free for all your customers to buy from you have to. I recommend that you incorporate ecommerce features upon website and merely ask for that information have to have when somebody is putting in an order. When you loved this post and you want to receive more details regarding [http://www.mavsocial.com/ Social Media Digital Asset Management] kindly visit our own web-site.

Modulation - Revision history

en>JaconaFrere: Reverted 1 good faith edit by 115.117.131.253 using STiki

en>Oalp1003: /* Analog modulation methods */ corrected wrong preposition

en>Calumet96: /* List of common digital modulation techniques */