Gas Exchange experiment

P 24.2 Gas Exchange Experiments in a River with Different Halogenated Compounds... 

Table 24.5 Characteristic Data of Chemical Tracers Used for the Gas Exchange Experiment Nondimensional Henry s Law Constant, Ki3/vi, Molecular Diffusion Coefficient in Air, Dia, and Water, Diw, Octanol-Water Partition Coefficient, Kiow, All valid for 4°C (Data from Cirpka et al., 1993)...

Oyama, V. I. and Berdahl B. J. The Viking gas exchange experiment results from Chryse and Utopia surface samples. loumal of Geophysical Research 82 4669-4676 1977. 

As mentioned earlier, analytical separation devices based on GC instrumentation have already been used in various space applications such as atmospheric probes and surface landers. Table 17.1 contains a summary of planetary exploration missions by NASA (both atmospheric probes and landers) where GC instrumentation has been used. The Viking mission to Mars contained two landers equipped with various scientific instruments for in situ analysis of the Martian atmosphere and soU. One of the analytical devices utiUzed a GC with one packed column equipped with a TCD to analyze the gases released by the soil (the Gas Exchange experiment GEX) after digestion of a nutrient liquid. The... 

In this chapter we review recent developments, concentrating mostly on the effects of water stress because of its great importance, but trying where possible to identify general problems. As noted above, accumulation of ABA in leaves is common under stress, and we review its effects on gas exchange. If the sole direct effect of ABA were to reduce stomatal aperture, then assimilation rate would also decrease because of a lower intercellular partial pressure of C02,pi. Some experiments have suggested that pi is little affected by ABA and that the capacity for CO2 fixation has actually decreased. The situation has become complicated with the observation (Terashima et al., 1988) that application of ABA can cause non-uniform... 

The operating steps are very similar as for a gas exchange, except that a defined partial pressure is maintained during the whole experiment. Care must be taken that any gaseous reaction products generated do not change the pressure set. If necessary the pressure must be controlled and kept constant by means of a manostat. 

Holmes, J.L. Mommers, A.A. Terlouw, J.K. Hop, C.E.C.A. The Mass Spectrometry of Neutral Species Produced From Mass-Selected Ions by Collision and by Charge Exchange. Experiments With Tandem Collision Gas Cells. Int. J. Mass Spectrom. Ion Proc. 1986, 68,249-264. 

Kim, Y., H. Sievering, J. Boatman, D. Wellman, and A. Pszenny, Aerosol Size Distribution and Aerosol Water Content Measurements during Atlantic Stratocumulus Transition Experiment Marine Aerosol and Gas Exchange, J. Geophys. Res., 100, 23027-23038 (1995). 

Cirpka, O., P. Reichert, O. Wanner, S. R. Muller, and R. P. Schwarzenbach, Gas exchange at river cascades Field experiments and model calculations , Environ. Sci. Technol., 27,2086-2097 (1993). 

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