Sorption and permeation of several organic vapours in poly(dimethylsiloxane) were investigated. Solubility and permeability coefficients measured show a strong dependence of the applied vapour activity typical for these systems, contrary to the behaviour of permanent gases. However, as irregularities in the series of chloromethanes show, highest sorption does not necessarily lead to the highest...

A major challenge that arises when growing GaN substrates in a single run process is the remaining curvature of the freestanding material after the removal of the foreign substrate. For a long time the dislocation density gradient has been suspected to be the cause. However, by conducting etching experiments, we have found that this cannot be the only reason. We postulate that the initial strai...

Thick GaN layers have been grown by hydride vapor phase epitaxy (HVPE) on different GaN templates grown by metalorganic vapor phase epitaxy. Crack formation could be reduced by using a hydrogen/nitrogen carrier gas mixture. By carefully optimizing the growth conditions in the final stage of the process, excellent surface morphologies could be obtained at still acceptably high growth rates. Up t...

(Subcooled) liquid vapour pressures and heat of vaporization of low-volatility isomeric organic compounds (tetrachlorobenzyltoluenes, TCBTs) were determined by two gas-liquid chromatographic (GLC) methods, By the first method vapour pressures and temperature-independent heats of vaporization of nine TCBTs were obtained at experimental temperatures (433.15-493.15 K) and linearly extrapolated to ...

The isotope signatures registered in speleothems during tropical cyclones (TC) provides information about the frequency and intensity of past TCs but the precise relationship between isotopic composition and the meteorology of TCs remain uncertain. Here we present continuous δ18O and δ2H data in rainfall and water vapour, as well as in discrete rainfall samples, during the passage of TC Ita and...

the aim of this study is to find the optimal water pressure and percentage of supply vapour in the feed water heaters (fwhs) of steam power plants, such that they maximize the thermal efficiency of the rankine cycle within pre-specified values of minimum and maximum pressures of the thermodynamic cycle. thermal efficiency is defined as a function of unknown variables (fluid pressure and vapour ...