- high-resolution terminology - matching measurements at high-resolution
Advancement per volume
Description
Advancement per volume or volume-specific advancement, dtrY [mol∙V-1], is related to advancement, dtrY = dtrξ∙V-1, as is the amount of substance per volume, ci (concentration) [mol∙V-1], related to amount, ci = = ni∙V-1. Advancement per volume is particularly introduced for chemical reactions, drY, where it has the dimension of a concentration. In an open system at steady-state, however, the concentration does not change as the reaction advances. Only in closed systems, specific advancement is the change in concentration divided by the stoichiometric number, ΔrY = Δci/νi. In general, Δci is replaced by the partial change of concentration, Δrci, which contributes to the total change of concentration, Δci. In open systems at steady-state, Δrci is compensated by external processes, Δextci, exerting an effect on the total concentration change, Δci = Δrci + Δextci = 0.
Abbreviation: dtrY
Reference: Gnaiger_1993_Pure Appl Chem
Application in respirometry
- In typical liquid phase reactions the volume of the system does not change during the reaction. When oxygen consumption (νO2 = -1 in the chemical reaction) is measured in aqueous solution, then the volume-specific oxygen flux is the time derivative of the advancement of the reaction per volume [1], JV,O2 = drYO2/dt = drξO2/dt∙V-1 [(mol∙s-1)∙L-1]. The rate of O2 concentration change is dcO2/dt [(mol∙L-1)∙s-1], where concentration is cO2 = nO2∙V-1. There is a difference between (1) JV,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].
MitoPedia concepts: Ergodynamics
