Laplace expansion (potential): Difference between revisions

Revision as of 14:48, 9 December 2013

Equilibrium isotope fractionation is the partial separation of isotopes between two or more substances in chemical equilibrium. Equilibrium fractionation is strongest at low temperatures, and (along with kinetic isotope effects) forms the basis of the most widely used isotopic paleothermometers (or climate proxies): D/H and ¹⁸O/¹⁶O records from ice cores, and ¹⁸O/¹⁶O records from calcium carbonate. It is thus important for the construction of geologic temperature records.^[1] Isotopic fractionations attributed to equilibrium processes have been observed in many elements, from hydrogen (D/H) to uranium (²³⁸U/²³⁵U). In general, the light elements (especially hydrogen, boron, carbon, nitrogen, oxygen and sulfur) are most susceptible to fractionation, and their isotopes tend to be separated to a greater degree than heavier elements.

Most equilibrium fractionations are thought to result from the reduction in vibrational energy (especially zero-point energy) when a more massive isotope is substituted for a less massive one. This leads to higher concentrations of the massive isotopes in substances where the vibrational energy is most sensitive to isotope substitution, i.e., those with the highest bond force constants.

In a reaction involving the exchange of two isotopes, ^lX and ^hX, of element "X" in molecules AX and BX,

A^{l} X + B^{h} X ⇌ A^{h} X + B^{l} X

each reactant molecule is identical to a product except for the distribution of isotopes (i.e., they are isotopologues). The amount of isotopic fractionation in an exchange reaction can be expressed as a fractionation factor:

α = \frac{(^{h} X /^{l} X)_{A X}}{(^{h} X /^{l} X)_{B X}}

$α = 1$ indicates that the isotopes are distributed evenly between AX and BX, with no isotopic fractionation. $α > 1$ indicates that ^hX is concentrated in substance AX, and $α < 1$ indicates ^hX is concentrated in substance BX. $α$ is closely related to the equilibrium constant (K_eq):

α = (K_{e q} \cdot Π σ_{P r o d u c t s} / Π σ_{R e a c t a n t s})^{1 / n}

where $Π σ_{P r o d u c t s}$ is the product of the rotational symmetry numbers of the products (right side of the exchange reaction), $Π σ_{R e a c t a n t s}$ is the product of the rotational symmetry numbers of the reactants (left side of the exchange reaction), and $n$ is the number of atoms exchanged.

An example of equilibrium isotope fractionation is the concentration of heavy isotopes of oxygen in liquid water, relative to water vapor,

H_{2}^{16} O_{(l)} + H_{2}^{18} O_{(g)} ⇌ H_{2}^{18} O_{(l)} + H_{2}^{16} O_{(g)}

At 20 °C, the equilibrium fractionation factor for this reaction is

α = \frac{(^{18} O /^{16} O)_{L i q u i d}}{(^{18} O /^{16} O)_{V a p o r}} = 1.0098

Equilibrium fractionation is a type of mass-dependent isotope fractionation, while mass-independent fractionation is usually assumed to be a non-equilibrium process.

For non-equilibrium reactions, isotopic effects are better described by the GEBIK and GEBIF equations for transient kinetic isotope fractionation, which generalize non-steady isotopic effects in any chemical and biochemical reactions.^[2]

References

↑ One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
↑ Maggi F. and W. J. Riley, (2010), Mathematical treatment of isotopologue and isotopomer speciation and fractionation in biochemical kinetics, Geochim. Cosmochim. Acta, 21 year-old Glazier James Grippo from Edam, enjoys hang gliding, industrial property developers in singapore developers in singapore and camping. Finds the entire world an motivating place we have spent 4 months at Alejandro de Humboldt National Park.

Chacko T., Cole D.R., and Horita J. (2001) Equilibrium oxygen, hydrogen and carbon isotope fractionation factors applicable to geologic systems. Reviews in Mineralogy and Geochemistry, v. 43, p. 1-81.

Horita J. and Wesolowski D.J. (1994) Liquid-vapor fractionation of oxygen and hydrogen isotopes of water from the freezing to the critical temperature. Geochimica et Cosmochimica Acta, v. 58, p. 3425-2437.

External links

AlphaDelta: Stable Isotope fractionation calculator - http://www2.ggl.ulaval.ca/cgi-bin/isotope/generisotope.cgi

[Urey_1947-1] One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang

[2] Maggi F. and W. J. Riley, (2010), Mathematical treatment of isotopologue and isotopomer speciation and fractionation in biochemical kinetics, Geochim. Cosmochim. Acta, 21 year-old Glazier James Grippo from Edam, enjoys hang gliding, industrial property developers in singapore developers in singapore and camping. Finds the entire world an motivating place we have spent 4 months at Alejandro de Humboldt National Park.

[1]

[2]

@@ Line 1: / Line 1: @@
-Wilber Berryhill is the name his parents gave him and he totally digs that title. Invoicing is what I do for a living but I've usually wanted my own company. Ohio is where her house is. What I love doing is football but I don't have the time lately.<br><br>My site :: online reader [[http://checkmates.co.za/index.php?do=/profile-56347/info/ click the up coming site]]
+Equilibrium isotope [[fractionation]] is the partial separation of [[isotopes]] between two or more substances in [[chemical equilibrium]]. '''Equilibrium fractionation''' is strongest at low temperatures, and (along with [[kinetic isotope effect]]s) forms the basis of the most widely used isotopic [[paleothermometer]]s (or [[proxy (climate)|climate proxies]]): [[deuterium|D/H]] and [[oxygen isotope ratio cycle|<sup>18</sup>O/<sup>16</sup>O]] records from [[ice cores]], and <sup>18</sup>O/<sup>16</sup>O records from calcium carbonate. It is thus important for the construction of [[geologic temperature record]]s.<ref name='Urey_1947'>{{cite journal | author=H. C. Urey | year=1947 | journal=J. Chem. Soc. | title=The Thermodynamic Properties of Isotopic Substances | pages=562–581 | doi=10.1039/JR9470000562 }}</ref> Isotopic fractionations attributed to equilibrium processes have been observed in many elements, from hydrogen ([[deuterium|D/H]]) to uranium ([[Isotopes of uranium|<sup>238</sup>U/<sup>235</sup>U]]). In general, the light elements (especially [[hydrogen]], [[boron]], [[carbon]], [[nitrogen]], [[oxygen]] and [[sulfur]]) are most susceptible to fractionation, and their isotopes tend to be separated to a greater degree than heavier elements.
+Most equilibrium fractionations are thought to result from the reduction in vibrational energy (especially [[zero-point energy]]) when a more massive isotope is substituted for a less massive one. This leads to higher concentrations of the massive isotopes in substances where the vibrational energy is most sensitive to isotope substitution, i.e., those with the highest bond force constants.
+In a reaction involving the exchange of two isotopes, <sup>l</sup>X and <sup>h</sup>X, of element "X" in [[molecule]]s AX and BX,
+:<math>A^lX + B^hX \rightleftharpoons A^hX + B^lX</math>
+each reactant molecule is identical to a product except for the distribution of isotopes (i.e., they are [[isotopologue]]s). The amount of isotopic fractionation in an exchange reaction can be expressed as a fractionation factor:
+:<math>\alpha = \frac{(^hX/^lX)_{AX}}{(^hX/^lX)_{BX}}</math>
+<math>\alpha = 1</math> indicates that the isotopes are distributed evenly between AX and BX, with no isotopic fractionation. <math>\alpha > 1</math> indicates that <sup>h</sup>X is concentrated in substance AX, and <math>\alpha < 1 </math> indicates <sup>h</sup>X is concentrated in substance BX. <math>\alpha</math> is closely related to the [[equilibrium constant]] (K<sub>eq</sub>):
+:<math>\alpha = (K_{eq} \cdot \Pi \sigma_{Products}/ \Pi \sigma_{Reactants})^{1/n}</math>
+where <math>\Pi\sigma_{Products}</math> is the product of the rotational symmetry numbers of the products (right side of the exchange reaction), <math>\Pi\sigma_{Reactants}</math> is the product of the rotational symmetry numbers of the reactants (left side of the exchange reaction), and <math>n</math> is the number of atoms exchanged.
+An example of equilibrium isotope fractionation is the concentration of heavy isotopes of [[oxygen]] in liquid [[water]], relative to [[water vapor]],
+:<math>H_2^{16}O_{(l)} + H_2^{18}O_{(g)} \rightleftharpoons H_2^{18}O_{(l)} + H_2^{16}O_{(g)}</math>
+At 20&nbsp;°C, the equilibrium fractionation factor for this reaction is
+:<math>\alpha = \frac{(^{18}O/^{16}O)_{Liquid}}{(^{18}O/^{16}O)_{Vapor}} = 1.0098 </math>
+Equilibrium fractionation is a type of mass-dependent isotope fractionation, while [[mass-independent fractionation]] is usually assumed to be a non-equilibrium process.
+For non-equilibrium reactions, isotopic effects are better described by the GEBIK and GEBIF equations for [[transient kinetic isotope fractionation]], which generalize non-steady isotopic effects in any chemical and biochemical reactions.<ref>Maggi F. and W. J. Riley, (2010), Mathematical treatment of isotopologue and isotopomer speciation and fractionation in biochemical kinetics, Geochim. Cosmochim. Acta, {{doi|10.1016/j.gca.2009.12.021}}</ref>
+==See also==
+[[Stable isotope]]<br />
+[[Standard electrode potential]]<br/>
+[[Isotope geochemistry]]<br />
+[[Kinetic isotope effect]]<br />
+[[Isotope analysis]]<br />
+[[Isotope electrochemistry]]<br />
+[[D18O|δ<sup>18</sup>O]]<br />
+[[Kinetic fractionation]]<br />
+[[Mass-independent fractionation]] <br />
+[[Transient kinetic isotope fractionation|Transient kinetic isotope effect]]<br />
+[[Transient kinetic isotope fractionation|Isotopic ratio]]<br />
+[[Transient kinetic isotope fractionation|Isotopic composition]]<br />
+[[Transient kinetic isotope fractionation|Fractionation factor]]<br />
+[[Transient kinetic isotope fractionation|Isotopic enrichment]]
+== References ==
+<references/>
+Chacko T., Cole D.R., and Horita J. (2001) Equilibrium oxygen, hydrogen and carbon isotope fractionation factors applicable to geologic systems. Reviews in Mineralogy and Geochemistry, v. 43, p.&nbsp;1-81.
+Horita J. and Wesolowski D.J. (1994) Liquid-vapor fractionation of oxygen and hydrogen isotopes of water from the freezing to the critical temperature. Geochimica et Cosmochimica Acta, v. 58, p.&nbsp;3425-2437.
+==External links==
+AlphaDelta: Stable Isotope fractionation calculator - http://www2.ggl.ulaval.ca/cgi-bin/isotope/generisotope.cgi
+[[Category:Isotope separation]]
+[[Category:Geochemistry]]

Laplace expansion (potential): Difference between revisions

Revision as of 14:48, 9 December 2013

See also

References

External links

Navigation menu

Search