We present vapor pressure data of the C2 to C5 dicarboxylic acids deduced from measured evaporation rates of single levitated particles as both, aqueous droplets and solid crystals. The data of aqueous solution particles over a wide concentration range allow us to directly calculate activities of the dicarboxylic acids and comparison of these activities with parameterizations reported in the li...

The influence of the unlike Lennard-Jones (LJ) parameters on vapor-liquid equilibria of mixtures is investigated and the performance of eleven combining rules is assessed. In the first part of the work, the influence of the unlike LJ size and energy parameter on vapor pressure, bubble density and dew point composition is systematically studied for the mixtures CO+C2H6 and N2+C3H6, respectively....

We use standard thermodynamic relationships to demonstrate the accuracy of new vapor pressure measurements by using them in the calculation ofliquid-phase heat capacities and comparing the results with recently published experimental values. Results for the new alternative refrigerants Rl34a and R 123 are used as examples.

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous pollutants resulting from incomplete combustion and many fuel processing and storage operations. They are encountered in the environment in many forms, ranging from non-aqueous phase liquid and/or solid mixtures (i.e., NAPL and NAPS materials), to dissolved aqueous phase components, to adsorbed species on solid surfaces. The present work con...

The composition, vapour pressure, and heat capacity of nine biodiesel fuels from different sources were measured. The vapour pressure of the biodiesel fuels is modeled assuming an ideal liquid phase of the fatty acid methyl esters constituting the fuel. New methodologies to calculate the vapour pressure and ideal gas and liquid heat capacities of the biodiesel fuel constituents are proposed. Tw...

Most methods of measuring the diffusive conductance to water vapor of individual plant leaves potentially change the leaf environment by enclosing part of the leaf in order to measure the rate of water vapor exchange and the driving force for that exchange. There have been questions about whether leaf to air water vapor pressure difference varies sufficiently in extensive crop canopies to be a ...

The atmospheric oxidation of monoterpenes plays a central role in the formation of secondary organic aerosols (SOAs), which have important effects on the weather and climate. However, models of SOA formation have large uncertainties. One reason for this is that SOA formation depends directly on the vapor pressures of the monoterpene oxidation products, but few vapor pressures have been reported...

Conventional control techniques are not able to accomplish the stable cooling in vapor compression air conditioning system. This paper describes the fuzzy models of refrigerating compressor, expansion valve, evaporator and condenser as basic elements of vapor compression air conditioning system. Compressor speed, delivery pressure, refrigerant flow rate, valve opening area, pressure difference ...

Calculations of self-broadened half-widths and self-induced pressure shifts are made using the complex Robert–Bonamy formalism. The results of calculations using different approximations of the intermolecular potential indicate that this is a strong collision system. The effects of the imaginary components on the half-widths are studied. The temperature, vibrational, and rotational state depend...

We have performed open cell transmission electron microscopy experiments through pure water vapor in the saturation pressure regime (>0.6 kPa), in a modern microscope capable of sub-Å resolution. We have systematically studied achievable pressure levels, stability and gas purity, effective thickness of the water vapor column and associated electron scattering processes, and the effect of gas pr...