Experiments and CFD-PBM simulation were performed in this study to investigate the effects of helically-finned tube (HFT) internals on gas-liquid flow a laboratory-scale bubble column. Hydrodynamic parameters, including gas holdup, size field as well turbulence properties, compared for an empty column other two columns with bare-tube (BT) or HFT internals. We found that bare rods promote stabil...

A robust nonlinear control law is designed to reject unknown feed composition disturbances with overall stability. Implementation to real columns as well as comparisons with classical control strategies, show the robustness and flexibility improvements of the method. Almtracq-Using singular perturbation techniques on a physical model of distillation column, an aggregated model is proposed for c...

This work provides a review of hydrodynamic characteristics and mass transfer in the K?hni extraction columns. The experiments, as reported literature, were performed presence absence transfer. results showed that Sauter mean drop diameter was strongly affected by rotor speed interfacial tension, whereas effects dispersed continuous velocities negligible. Empirical correlations for diameter, ta...

The most prominent aspect of multiphase flow is the variation in the physical distribution of the phases in the flow conduit known as the flow pattern. Several different flow patterns can exist under different flow conditions which have significant effects on liquid holdup, pressure gradient and heat transfer. Gas-liquid two-phase flow in an annulus can be found in a variety of practical situat...

A holdup problem on workers’ skill investment arises when employers can adopt discriminatory hiring norm to extract higher than socially optimal profit. In such an economy, productivity (skills) and non-productivity oriented characteristics (discrimination) both matter when determining which worker has priority. The resulting firms’ preference is an intertwined ranking order, by virtue of which...

We argued in our article, Patent Holdup and Royalty Stacking, that the threat to obtain a permanent injunction can greatly enhance a patent holder’s negotiating power, leading to royalty rates that exceed a benchmark level based on the value of the patented technology and the strength of the patent. Our analysis showed that such problems are especially likely to arise for patents covering a min...