Oxygen utilization rate

Jenkins W. J. (1982) Oxygen utilization rates in North Atlantic subtropical gyre and primary production in oligotrophic systems. Nature 300, 246-248. 

Physical processes, however, are a common determinant for the distributions of all geochemical distributions, and their quantification may lead to insight into the magnitude aznd nature of the other processes. For example, determination of tracer ventilation rates has been used to quantify oxygen utilization rates, which in turn can be used to estimate export production in the ocean (Jenkins, 1984 Jenkins and Wallace, 1992). 

Jenkins W. J. (1987) H and He in the beta triangle observations of gyre ventilation and oxygen utilization rates. J. Phys. Oceanogr. 17, 763-783. 

A) A schematic cross section of the upper ocean, illustrating surface water values and trends on subsurface isopycnals for O2, AOU, preformed nutrients, P , and time since the water mass was at the surface, t. (B) Schematic plots of O2, P, AOU and t versus locations 1,2,3 and 4 in (A) and a plot of AOU versus t used to derive oxygen utilization rates (OUR). 

Jean-Baptiste P, Petit JR, Lipenkov VY, Raynaud D, Barkov N (2001) Constraints on hydrothermal processes and water exchange in Lake Vostok from helium isotopes. Nature 411 460-462 Jean-Baptiste P, Raynaud D, Mantisi F, Sowers T, Barkov N (1993) Measurement of helium isotopes in Antarctic ice preliminary results from Vostok. C R Acad Sci Paris 316 491-497 Jenkins WJ (1976) Tritium-helium dating in the Sargasso Sea A measurement of oxygen utilization rates. Science 196 291-292... 

Apparent oxygen utilization rates from the central Arctic that are so high, they need to be balanced by transport of high production water from over the continental shelves. 

Figure 12 Apparent oxygen utilization plotted against measured A C for WOCE Pacific Ocean samples taken at depths greater than 4000 m and north of 40°S. The slope of the line (-0.831+0.015) can be used to estimate an approximate oxygen utilization rate of 0.1 pmol kg y if steady state and no mixing with other water masses is assumed.

Sonnerup RE, Quay PD, and Bullister JL (1999) Ther-mocline ventilation and oxygen utilization rates in the subtropical North Pacific based on CFG distributions during WOCE. Deep-Sea Research 146 777-805. 

The working reactor volume is 20 ml Therefore, = 225/20,000 1.1 x 10" W/kg. This value is sufficiently low for use in animal cell bioreactors. The low power requirement can be attributed to the relatively very low wm used. The low vvm in turn is a result of the much lower oxygen utilization rate (lower peak OUR/higher doubling times as compared to bacteria/yeast in Table 7B.6 in such systems). 

The water management burden is not limited to preventing membrane dryout. The need to operate at relatively high oxygen utilization rates (relatively low air flow rates) increases the tendency to form water droplets within the cell from the formation of product water at the cathode. This can lead to accumulation of water on the surface of or within the electrode substrate or in the air distribution channels of the cathode flow-field. Such events could result in serious performance losses from the ensuing restriction of air access to impacted regions of the electrocatalyst. Consequently, the cell design approach must also serve to prevent such accumulation of water droplets. 

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