Dissociation of proton bound ketone dimers in asymmetric electric fields with differential mobility spectrometry and in uniform electric fields with linear ion mobility spectrometry.

The kinetics for the decomposition of the symmetrical proton-bound dimers of a series of 2-ketones (M) from acetone to 2-nonanone have been determined at ambient pressure by linear ion mobility spectrometry (IMS) and by differential mobility spectrometry (DMS). Decomposition, M2H(+) →MH(+) + M, in the IMS instrument, observed under thermal conditions over the temperature range 147 to 172 °C, yielded almost identical Arrhenius parameters Ea = 122 kJ mol(-1) and ln A = 38.8 for the dimers of 2-pentanone, 2-heptanone, and 2-nonanone. Ion decomposition in the DMS instrument was due to a combination of thermal and electric field energies at an effective ion internal temperature whose value was estimated by reference to the IMS kinetic parameters. Decomposition was observed with radio frequency (RF) fields with maximum intensities in the range 10 kV cm(-1) to 30 kV cm(-1) and gas temperatures from 30 to 110 °C, which yielded effective temperatures that were higher than the gas temperature by 260° at 30 °C and 100° at 110 °C. There was a mass dependence of the field for the onset of decomposition: the higher the ion mass, the higher the required field at a given gas temperature, which is ascribed to the associated increasing heat capacity with the increasing carbon number, but similar, internal vibrations and rotations.

Robust design of a 2-DOF GMV controller: a direct self-tuning and fuzzy scheduling approach.

This paper presents a study on self-tuning control strategies with generalized minimum variance control in a fixed two degree of freedom structure-or simply GMV2DOF-within two adaptive perspectives. One, from the process model point of view, using a recursive least squares estimator algorithm for direct self-tuning design, and another, using a Mamdani fuzzy GMV2DOF parameters scheduling technique based on analytical and physical interpretations from robustness analysis of the system. Both strategies are assessed by simulation and real plants experimentation environments composed of a damped pendulum and an under development wind tunnel from the Department of Automation and Systems of the Federal University of Santa Catarina.