This work is focused on the evaluation of oxygen semi-permeation and electrochemical performances under high oxygen gradient of free cobalt perovskite membrane materials; La1−xSrxFeO3−δ perovskite. For a better understanding of oxygen transport through La1−xSrxFeO3−δ perovskite membranes, the oxygen diffusion, oxygen incorporation, and desorption coefficients were determined under high oxygen gradient in relation to the temperature for La1−xSrxFeO3−δ (with x = 0.1, 0.3, 0.5, and 0.7) by a specific method based on oxygen semi-permeation. The best electrochemical performances were obtained for La0.3Sr0.7FeO3−δ (LSF37) and La0.5Sr0.5FeO3−δ (LSF55) perovskite membranes with oxygen fluxes of 1.7 × 10−3 and 1.2 × 10−3 mol/m2 s at 900 °C, respectively. The oxygen incorporation and desorption coefficients of LSF55 were two times lower than those of LSF37 and similar to those of La0.5Sr0.5Fe0.7Ga0.3O3−δ. The values of these coefficients are discussed and compared with the data reported in the literature by isotopic exchange for the similar material compositions.

We have performed O self-diffusion experiments in synthetic diopside single crystals along the b-axis at temperatures ranging from 1473–1643 K, under controlled O partial pressure (10−11–10−2 atm). The 18O tracer diffusion was imposed by solid/gas exchange between 16O in diopside and 18O2-enriched argon-hydrogen-H2O gas mixture. Diffusion profiles of 18O were measured by Nuclear Reaction Analysis 18O (p,α) 15N. The diffusion coefficients are described by , with log D0(m2/s)=−9.2 ± 1.0 and E 310 ± 30 kJ/mol.

Our results are in agreement with Ryerson and McKeegan's (1994) data and Farver's (1989) data along a direction perpendicular to the c direction. Experiments performed in a wide pO2 range show that D is independent of pO2.

We observe no change in the diffusion regime up to 1643 K (i.e. 22 K prior to melting temperature). This result differs from the diffusion study of Ca in diopside by Dimanov and Ingrin (1995), where a strong enhancement of Ca mobility, attributed to an excess disorder in the Ca-sublattice, was observed above 1523 K. We conclude that O diffusion in diopside is not affected by this premelting phenomenon.

This brief review examines the athletic potential of mammals in general and the horse in particular as it relates to oxygen (O2) transport and utilization. The horse has been bred selectively for over six millennia based upon its ability to run fast. Whereas this has optimized cardiovascular and muscle function and the capacity to deliver and utilize O2, it has resulted in lung failure during intense exercise. Horses in their athletic prime are considered and attention is focused on their maximal capacities as related to O2 transport, irrespective of age per se. Following a few comments on the history of O2, this review moves from established principles of O2 transport at the integrative organ level to the microcirculation and the processes and principles that govern O2 offloading, where much remains to be discovered. Four principal questions are addressed: (1) as an athlete, what are the most outstanding physiological characteristics of the horse? (2) what anatomical and physiological capacities facilitate this superlative performance and such prodigious O2 fluxes (i.e. maximal VO2)? (3) do cardiovascular dynamics or intramuscular energetic processes limit VO2 kinetics (i.e. the speed at which VO2 increases at the onset of exercise)? VO2 kinetics determine the size of the O2 deficit and as such represent an important determinant of muscle metabolism and fatigue; and (4) what determines the efficacy of muscle microcirculatory O2 exchange?