Vapour-pressure deficit temperature, the relative humidity and, if possible, the canopy air temperature. We must then compute the saturation pressure. Saturation pressure can be looked up in a psychrometric chart or derived from the Arrhenius equation, a way to compute it directly from temperature is where: To convert between Rankine and degrees Fahrenheit: formula_10 We compute this pressure for both the ambient and canopy temperatures. We then can compute the actual partial pressure of the water vapour in the air by multiplying by the relative humidity [%]: and finally VPD using formula_12 or formula_13 when the canopy temperature is known. Vapour-pressure deficit
Hydride vapour phase epitaxy source materials than in MOCVD, reducing the capital equipment costs, due to the high growth rate. Developed in the 1960s, it was the first epitaxial method used for the fabrication of single GaN crystals. Hydride Vapour Phase Epitaxy (HVPE) is the only III-V and III-N semiconductor crystal growth process working close to equilibrium. That means that the condensation reactions exhibit fast kinetics: one observe immediate reactivity to an increase of the vapour phase supersaturation towards condensation. This property is due to the use of chloride vapour precursors GaCl and InCl, of which dechlorination frequency is high enough so that there