Experimental evidence of a delta-shock in nonlinear chromatography.

We report about a new type of composition front in nonlinear chromatography that is called delta-shock, which has to be added to the family of classical transitions, i.e. simple waves, shocks and semi-shocks.

The direct inverse method: a novel approach to estimate adsorption isotherm parameters.

A novel method to estimate adsorption isotherm parameters is presented and its applicability is studied through synthetic as well as experimental data. This approach assumes a linear dependency of the UV absorption intensity on the solute concentration in the fluid phase, at least in certain ranges of the UV spectra. It was demonstrated that by fitting the absorption profiles, i.

Calibration-free quantitative application of in situ Raman spectroscopy to a crystallization process.

In this work, in situ Raman spectroscopy is applied in a quantitative manner to crystal suspensions during crystallization in order to monitor a solvent-mediated polymorph transformation without the use of a calibration model. Assuming a linear dependency of the Raman signal intensity on the solute and on the solid concentrations of both solid-state forms, the measured time-resolved Raman spectra are fitted directly using a detailed model that describes the time evolution of the process. The applicability of this novel method is demonstrated thoroughly through the application to synthetic data of unseeded and seeded transformations as well as to various seeded polymorph transformation experiments.

Inhibition of nonlinear acoustic cavitation dynamics in liquid CO2.

The authors present a model to study ultrasound-induced cavitation dynamics in liquid carbon dioxide (CO(2)), which includes descriptions for momentum, mass, and energy transport. To assist in the interpretation of these results, numerical simulations are presented for an argon cavity in water. For aqueous systems, inertia effects and force accumulation lead to a nonlinear radial motion, resulting in an almost adiabatic compression of the cavity interior.