We study experimentally the dynamical behavior of few large tracer particles placed in a quasi-2D granular ``gas'' made many small beads low-gravity environment. Multiple inelastic collisions transfer momentum from uniaxially driven gas to tracers whose velocity distributions are studied through particle tracking. Analyzing these for an increasing system density reveals that translational energ...

Tracer gas studies and oxygen uptake measurements have shown that pressurized gas transport improves oxygen supply to roots in the wetland tree species Taxodium distichum L. Rich. (Taxodiaceae), Betula pubescens J.F. Ehrh. (Betulaceae), and Populus tremula L. (Salicaceae), but not in Acer pseudoplatanus L. and Ilex aquifolium L., which are found in drier habitats. In the deciduous tree species ...

The ventilation rate is an important parameter for assessing indoor air quality and energy efficiency. In occupied buildings, measurements utilising passive methods are preferable to active due their simplicity less intrusive nature. perfluorocarbon tracer method can be used measure long-term rates this purpose. This requires the release of a gas which often liquid chemical diffusing out vial. ...