Advancement

high-resolution terminology - matching measurements at high-resolution

Advancement

Description

In an isomorphic analysis, any form of flow is the advancement of a process per unit of time, expressed in a specific motive unit [MU∙s^-1], e.g., ampere for electric flow or current [A≡C∙s^-1], watt for heat flow [W≡J∙s^-1], and for chemical flow the unit is [mol∙s^-1]. The corresponding isomorphic forces are the partial exergy (Gibbs energy) changes per advancement [J∙MU^-1], expressed in volt for electric force [V≡J∙C^-1], dimensionless for thermal force, and for chemical force the unit is [J∙mol^-1], which deserves a specific acronym ([Jol]) comparable to volt. For chemical processes of reaction and diffusion, the advancement is the amount of motive substance [mol]. The concept was originally introduced by De Donder. Central to the concept of advancement is the stoichiometric number, ν_X, associated with each motive component X (transformant [1]).

In a chemical reaction, r, the motive entity is the stoichiometric amount of reactant, d_rn_X, with stoichiometric number ν_X. The advancement of the chemical reaction, d_rξ [mol], is then defined as

drξ = drnX·νX-1

The flow of the chemical reaction, I_r [mol·s^-1], is advancement per time,

Ir = drξ·dt-1

Abbreviation: d_trξ

Reference: Gnaiger_1993_Pure Appl Chem

Communicated by Gnaiger E 2018-10-16

Advancement per volume

In typical liquid phase reactions the volume of the system does not change during the reaction. When oxygen consumption is measured (ν_O2 = -1 in the chemical reaction), then the volume-specific oxygen flux is the time derivative of the advancement of the reaction per unit volume [1], J_V,O2 = d_rξ_O2/dt∙V^-1 [(mol∙s­^-1)∙L­^-1]. The rate of O₂ concentration change is dc_O2/dt [(mol∙L­^-1)∙s­^-1], where concentration is c_O2 = n_O2/V. There is a difference between (1) J_V,O2 [mol∙s­^-1∙L­^-1] and (2) rate of concentration change [mol∙L­^-1∙s­^-1]. These merge to a single expression only in a closed system. In open systems, internal transformations (catabolic flux, O₂ consumption) are distinguished from external flux (such as O₂ supply). External fluxes of all substances are zero in closed systems [2].

References

1. Gnaiger E (1993) Nonequilibrium thermodynamics of energy transformations. Pure Appl Chem 65:1983-2002. - »Bioblast link«
2. MitoEAGLE preprint 2018-10-16(43) Mitochondrial respiratory states and rates: Building blocks of mitochondrial physiology Part 1. - www.mitoeagle.org/index.php/MitoEAGLE_preprint_2018-02-08

MitoPedia concepts: MiP concept, Ergodynamics