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Difference between revisions of "Work"

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{{MitoPedia
{{MitoPedia
|abbr=''W'' [J]
|abbr=d<sub>e</sub>''W'' [J]
|description='''Work''' [J] is a specific form of [[energy]], called [[exergy]], performed by a closed or open system on its surroundings (the environment). This is the definition of ''external'' work, which is zero in [[isolated system]]s. The term exergy includes external and internal work. Mechanical work is force [N] times path length [m]. The internal-energy change of a closed system, d''U'', is due to exchange (e) of work and heat, and work is the internal-energy change minus heat,
|description='''Work''' [J] is a specific form of [[energy]], called [[exergy]], performed by a closed or open system on its surroundings (the environment). This is the definition of ''external'' work, which is zero in [[isolated system]]s. The term exergy includes external and internal work. Mechanical work is force [N] times path length [m]. The internal-energy change of a closed system, d''U'', is due to external exchange (e) of work and heat, and work is the internal-energy change minus heat,
  d<sub>et</sub>''W'' = d''U'' - d<sub>e</sub>''Q''
  d<sub>et</sub>''W'' = d''U'' - d<sub>e</sub>''Q''
|info=[[Gnaiger_1993_Pure Appl Chem |Gnaiger (1993) Pure Appl Chem]]
|info=[[Gnaiger_1993_Pure Appl Chem |Gnaiger (1993) Pure Appl Chem]]
}}
}}
  Communicated by [[Gnaiger E]] 2018-10-20; last update 2018-12-29
  Communicated by [[Gnaiger E]] 2018-10-20; last update 2019-01-06


== Pressure-volume work ==
== Pressure-volume work ==
:::: Pressure-volume work, d<sub>''V''</sub>''W'', at constant pressure, is the gas pressure, ''p'' [Pa = J·m<sup>-3</sup>], times volume, ''V'' [m<sup>3</sup>],
:::: Pressure-volume work, d<sub>''V''</sub>''W'', at constant pressure, is the gas pressure, ''p'' [Pa = J·m<sup>-3</sup>], times change of volume, d''V'' [m<sup>3</sup>],
  d<sub>''V''</sub>''W'' = -''p''·d''V'' [J]
  d<sub>''V''</sub>''W'' = -''p''·d''V'' [J]
:::: The ''available'' work, d<sub>e</sub>''W'', is distinguished from external total work as [1]
:::: The ''available'' work, d<sub>e</sub>''W'', is distinguished from external total work as [1]
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:::: The [[enthalpy]] change, d''H'', at constant pressure, is defined as internal-energy change minus pressure-volume work,
:::: The [[enthalpy]] change, d''H'', at constant pressure, is defined as internal-energy change minus pressure-volume work,
  d''H'' = d''U'' - d<sub>''V''</sub>''W''
  d''H'' = d''U'' - d<sub>''V''</sub>''W''
{{Keywords: Energy and exergy}}


== References ==
== References ==
:::# Gnaiger E (1993) Nonequilibrium thermodynamics of energy transformations. Pure Appl Chem 65:1983-2002. - [[Gnaiger 1993 Pure Appl Chem |»Bioblast link«]]
:::# Gnaiger E (1993) Nonequilibrium thermodynamics of energy transformations. Pure Appl Chem 65:1983-2002. - [[Gnaiger 1993 Pure Appl Chem |»Bioblast link«]]


{{MitoPedia concepts
{{MitoPedia concepts
|mitopedia concept=Ergodynamics
|mitopedia concept=Ergodynamics
}}
}}

Revision as of 22:54, 17 February 2020


high-resolution terminology - matching measurements at high-resolution


Work

Description

Work [J] is a specific form of energy, called exergy, performed by a closed or open system on its surroundings (the environment). This is the definition of external work, which is zero in isolated systems. The term exergy includes external and internal work. Mechanical work is force [N] times path length [m]. The internal-energy change of a closed system, dU, is due to external exchange (e) of work and heat, and work is the internal-energy change minus heat,

detW = dU - deQ

Abbreviation: deW [J]

Reference: Gnaiger (1993) Pure Appl Chem

Communicated by Gnaiger E 2018-10-20; last update 2019-01-06

Pressure-volume work

Pressure-volume work, dVW, at constant pressure, is the gas pressure, p [Pa = J·m-3], times change of volume, dV [m3],
dVW = -p·dV [J]
The available work, deW, is distinguished from external total work as [1]
deW = detW - dVW
The enthalpy change, dH, at constant pressure, is defined as internal-energy change minus pressure-volume work,
dH = dU - dVW


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Click to expand or collaps
»Bioblast links: Energy and exergy - >>>>>>> - Click on [Expand] or [Collapse] - >>>>>>>
Units
  • Joule [J]; 1 J = 1 N·m = 1 V·C; 1 cal = 4.184 J
Fundamental relationships
» Energy
» Exergy
» Extensive quantity
Contrast
» Force
» Pressure
» Intensive quantity
Forms of energy
» Internal-energy dU
» Enthalpy dH
» Heat deQ
» Bound energy dB
Forms of exergy
» Helmholtz energy dA
» Gibbs energy dG
» Work deW
» Dissipated energy diD


References

  1. Gnaiger E (1993) Nonequilibrium thermodynamics of energy transformations. Pure Appl Chem 65:1983-2002. - »Bioblast link«


MitoPedia concepts: Ergodynamics