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Only propene and 1-propanol are observed as products of the acid-catalyzed dehydration of 2-propanol in compressed liquid water after 100 s or less at 320 °C. Likewise, only propene, 2-propanol, and traces of n-propyl ether are observed as products of the acid-catalyzed dehydration of 1-propanol under the same conditions. Kinetic analyses of the experimental data indicate that propene is formed from 1-propanol by an acid-catalyzed E2 mechanism that involves only protonated 1-propanol as an intermediate. Byproduct n-propyl ether is formed by an AdE3 mechanism involving propene, 1-propanol, and acid. The formation of propene from 2-propanol is kinetically consistent with both an acid-catalyzed E2 mechanism and an acid-catalyzed E1 mechanism (that involves the bare i-propyl cation in addition to protonated 2-propanol as intermediates in the dehydration chemistry). Thus, our kinetic analysis does not enable us to discriminate between the two mechanisms for 2-propanol dehydration. On the other hand, results of the kinetic analysis point to the important role of the undetected product i-propyl ether in the formation of propene from both 2-propanol and 1-propanol. This ether (which is not stable in hot liquid water) is formed by an AdE3 mechanism and decomposes via an uncatalyzed, unimolecular reaction. Experimental studies of the reactions of n-propyl ether and i-propyl ether are consistent with model predictions.

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This paper is an initial report on flight experiments with a small, unmanned helicopter using a state dependent Riccati Equation (SDRE) controller for autonomous, agile maneuvering. The control design is based upon a full, 6-DoF, analytic nonlinear dynamic model, which is manipulated into a pseudo-linear form in which system matrices are given explicitly as a function of the current state. A standard Riccati equation is then solved numerically in each frame of a 50 Hz. control loop to design the state feedback control law on-line. Several flights have been flown with the helicopter to evaluate the accuracy of tracking under SDRE control in comparison with simulation results.

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