The aerenchyma contributes to O2 supply from shoots to roots and to the ventilation of gases (e.g. CO2 and methane) from roots to shoots (Colmer 2003a; Evans 2003).
The ventilation of gases in aerenchyma is mainly caused by gas diffusion in rice, but in some wetland species with 'through-flow pathways' (e.g. along rhizomes), gas flows can also occur by humidity- and Venturi-induced pressure flows (e.g. Phragmites australis; Armstrong et al. 1996).
Furthermore, the increase of aerenchyma in leaf sheaths and internodes above constitutive levels might improve the ventilation of gases between roots and shoots under waterlogged soil conditions.
This second paper evaluates the effect of forced ventilation on gas cloud dispersion using CFD in order to evaluate possible design measures, such as safety distance in trains and whether to shut down the AFC in case of releases.
After the adoption of Y-type ventilation, the concentration of gas in return air was between 0.15 % and 0.64 % with a ventilation rate of 2100 2750 m3/min.
Tests of pulmonary function have been developed which can be used with small animals to measure spirometry (lung volumes), mechanics, distribution of ventilation, gas exchange or control of ventilation.
Plan for the ventilation of the exhaust gas.
Criteria to switch from CPAP to bi-level ventilation were a lack of improvement or a worsening of ventilation and/or gas exchange at a blood gas examination performed 30 minutes/1 hour after initiation of CPAP treatment, in the absence of criteria for endotracheal intubation (ETI).
Criteria for ETI were at least one among the following: impairment of consciousness; hemodynamic instability (systolic blood pressure <90 mmHg); cardiac and/or respiratory arrest; and a lack of improvement or a worsening of ventilation and/or gas exchange at a blood gas examination performed 1 hour after initiation of bi-level treatment.
In mixed-gas diving, inspired oxygen is therefore maintained at a partial pressure somewhere between 0.2 and 0.5 bar, but at great depths the inhomogeneity of alveolar ventilation and the limitations of gas diffusion appear to require oxygen provision at greater than normal levels.
