Biomaterial Database

Tritiated water vapor exchange in sunflowers. 1983

P Couchat, and M Puard, and G Lasceve

Water vapor exchange between sunflowers (Helianthus annuus L.) and the atmosphere was studied in darkness and in light using THO as a tracer. In the presence of tritiated water vapor, the exchange of THO measured as tritiated water in the leaves was slower in darkness than under illumination. This is explained by the variation of stomatal conductance. The authors show that a single curve is capable of summarizing the tritium exchange under any environmental condition, provided adequate units are used; this curve characterizes the behaviour of sunflowers with regard to tritiated water exchange. Using a numerical simulation model, we showed that the tritiated water vapor exchange is well represented by Fick's equation and affects only 80% of the total leaf water (lamina plus veins).

UI	MeSH Term	Description	Entries
D004780	Environment, Controlled	A state in which the environs of hospitals, laboratories, domestic and animal housing, work places, spacecraft, and other surroundings are under technological control with regard to air conditioning, heating, lighting, humidity, ventilation, and other ambient features. The concept includes control of atmospheric composition. (From Jane's Aerospace Dictionary, 3d ed)	Clean Rooms,Laminar Air-Flow Areas,Controlled Environment,Area, Laminar Air-Flow,Clean Room,Controlled Environments,Environments, Controlled,Laminar Air Flow Areas,Laminar Air-Flow Area,Room, Clean
D006368	Helianthus	A genus herbs of the Asteraceae family. The SEEDS yield oil and are used as food and animal feed; the roots of Helianthus tuberosum (Jerusalem artichoke) are edible.	Jerusalem Artichoke,Sunflower,Helianthus annuus,Helianthus tuberosus,Artichoke, Jerusalem,Sunflowers
D014316	Tritium	The radioactive isotope of hydrogen also known as hydrogen-3. It contains two NEUTRONS and one PROTON in its nucleus and decays to produce low energy BETA PARTICLES.	Hydrogen-3,Hydrogen 3
D014835	Volatilization	A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.	Vaporization,Volatility
D014867	Water	A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Hydrogen Oxide