scholarly journals An interpretation of the Mars spectrum taken by the Connes

1971 ◽  
Vol 40 ◽  
pp. 189-189 ◽  
Author(s):  
L. D. Kaplan ◽  
L. D. Gray Young
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Partial Pressure ◽  
Surface Pressure ◽  
Rotational Temperature ◽  
Martian Atmosphere ◽  
Co Concentration

Lines of the 2-0 and 3-0 bands of carbon monoxide and (many) bands of carbon dioxide appear prominently in the Connes' Mars spectrum [1]. Five carbon dioxide bands were measured to construct a curve of growth for CO2 lines formed in the Martian atmosphere [2]. A similar curve of growth was constructed for the 2-0 band of carbon monoxide. From these curves, we have computed the rotational temperature of the atmosphere, the surface pressure, and the abundance of CO and CO2. The surface pressure is found to be approximately equal to the CO2 partial pressure, i.e. ps ~ 5 mb. The CO concentration by volume was found to be slightly less than one part per thousand.

Geometrical Construction of Auxiliary Axes in an Ellingham Diagram

2020 ◽  
Vol 856 ◽  
pp. 1-7
Author(s):  
Thamrongsin Siripongsakul ◽  
Panya Wiman ◽  
Phichai Saranyachot ◽  
Somrerk Chandra-Ambhorn
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Partial Pressure ◽  
Equilibrium Partial Pressure ◽  
Geometrical Construction ◽  
Geometrical Method ◽  
Partial Pressures ◽  
Ellingham Diagram ◽  
Set Up ◽  
Thermodynamic Derivation

To facilitate the assessment of the oxide stability in H2-H2O or CO-CO2 atmospheres, auxiliary axes are constructed in the Ellingham diagram. Based on A. Ghosh’s approach, the geometrical interpretation of the diagram is proposed for the reaction 2X + O2 = 2Y, where X and Y could be originated from H2 and H2O or CO and CO2. Two cases are considered when oxygen partial pressures are lower and higher than one bar. By a geometrical method, it is proved that with an appropriate set-up of values relating to the auxiliary axes, the axes representing the ratio between the equilibrium partial pressure of hydrogen and that of water vapour, as well as the ratio between the equilibrium partial pressure of carbon monoxide and that of carbon dioxide, can be constructed. The geometrical method on the construction of axes using thermodynamic derivation is explained in the paper.

scholarly journals CO Metabolism in the Acetogen Acetobacterium woodii

2015 ◽  
Vol 81 (17) ◽  
pp. 5949-5956 ◽  
Author(s):  
Johannes Bertsch ◽  
Volker Müller
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Resting Cells ◽  
Acetobacterium Woodii ◽  
Content Type ◽  
Inhibition Of Growth ◽  
Acetogenic Bacteria ◽  
Carbon Substrates ◽  
Co Concentration ◽  
A Site

ABSTRACTThe Wood-Ljungdahl pathway allows acetogenic bacteria to grow on a number of one-carbon substrates, such as carbon dioxide, formate, methyl groups, or even carbon monoxide. Since carbon monoxide alone or in combination with hydrogen and carbon dioxide (synthesis gas) is an increasingly important feedstock for third-generation biotechnology, we studied CO metabolism in the model acetogenAcetobacterium woodii. When cells grew on H2-CO2, addition of 5 to 15% CO led to higher final optical densities, indicating the utilization of CO as a cosubstrate. However, the growth rate was decreased by the presence of small amounts of CO, which correlated with an inhibition of H2consumption. Experiments with resting cells revealed that the degree of inhibition of H2consumption was a function of the CO concentration. Since the hydrogen-dependent CO2reductase (HDCR) ofA. woodiiis known to be very sensitive to CO, we speculated that cells may be more tolerant toward CO when growing on formate, the product of the HDCR reaction. Indeed, addition of up to 25% CO did not influence growth rates on formate, while the final optical densities and the production of acetate increased. Higher concentrations (75 and 100%) led to a slight inhibition of growth and to decreasing rates of formate and CO consumption. Experiments with resting cells revealed that the HDCR is a site of CO inhibition. In contrast,A. woodiiwas not able to grow on CO as a sole carbon and energy source, and growth on fructose-CO or methanol-CO was not observed.

scholarly journals Ultraviolet polarization measurements of Mars and the opacity of the Martian atmosphere

1971 ◽  
Vol 40 ◽  
pp. 170-176
Author(s):  
Andrew P. Ingersoll
Keyword(s):  
Carbon Dioxide ◽  
Optical Depth ◽  
Surface Pressure ◽  
Rayleigh Scattering ◽  
Surface Albedo ◽  
Martian Atmosphere ◽  
Maximum Elongation ◽  
Fine Dust ◽  
Martian Surface ◽  
Best Fit

Ground-based polarimetric data taken near maximum elongation are presented. These data are analyzed assuming an optically thin, Rayleigh scattering atmosphere, and a surface whose polarization varies inversely as the surface albedo. The best fit to the data yields an optical depth for Rayleigh scattering corresponding to a surface pressure of 6 ± 1 mb, if carbon dioxide is the principal constituent. There is no need to postulate the existence of fine dust in the Martian atmosphere. This method is potentially capable of resolving elevation differences on the Martian surface.

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