Compiègne, France
Compiègne, France
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Breeden S.W.,University of York | Clark J.H.,University of York | Farmer T.J.,University of York | MacQuarrie D.J.,University of York | And 3 more authors.
Green Chemistry | Year: 2013

A range of carbohydrates has been rapidly and selectively converted to 5-chloromethyl furfural using microwave heating in a biphasic reaction system with a range of organic solvents. Fructose and inulin were especially effective for production of this valuable bio-platform molecule, with yields of >70% obtained in 15 minutes under microwave heating. Yields from cellulose were dramatically increased with ball mill pre-treatment, this being associated with a reduction in polysaccharide crystallinity. © 2013 The Royal Society of Chemistry.

Griffen J.A.,University of Bath | Le Coz A.M.,ESCOM | Kociok-Kohn G.,University of Bath | Khan M.A.,University of Bath | And 2 more authors.
Organic and Biomolecular Chemistry | Year: 2011

Metabolism of meta-bromobenzoic acid by the blocked mutant Ralstonia eutrophus B9 affords an enantiopure dearomatised halodiene-diol which we demonstrate is a versatile chiron for organic synthesis. The presence of the halogen leads to reactivity that is distinct to that observed for the non-halogenated analogue and also serves as a synthetic handle for further functionalisation. © 2011 The Royal Society of Chemistry.

Aguilar-Ibanez C.,Research Center en Computacion | Martinez J.C.,CINVESTAV | Rubio J.D.J.,ESIME Azcapotzalco | Suarez-Castanon M.S.,ESCOM
ISA Transactions | Year: 2015

The present paper concerns the induction of stable sustained oscillation in feedback-linearizable single-input affine nonlinear dynamical systems via continuous-time state feedback control. The proposed application-oriented control approach is based on the conception of a state feedback controller that ensures the tracking of a limit cycle characterized in terms of the feedback-linearized system. Boundedness and convergence of the closed-loop trajectories are established following the Lyapunov theoretical framework and applying LaSalle's stability principle. The proposed approach is demonstrated with computer-simulated control experiments, showing that it ensures the convergence of the state trajectories of the controlled system to a designed limit cycle and that the methodology can, in principle, be applied to any single input feedback linearizable system. © 2014 ISA.

Aguilar-Ibanez C.,CIC | Sira-Ramirez H.,CINVESTAV | Suarez-Castanon M.S.,ESCOM | Martinez-Navarro E.,CIC | Moreno-Armendariz M.A.,CIC
International Journal of Control | Year: 2012

In this article we present a flatness-based controller that solves the trajectory tracking problem for an unmanned four-rotor aircraft. A simple version of the dynamical system obtained from a suitable coordinate transformation of the Euler-Lagrange model of the system is used. This model, combined with a suitable input saturation nonlinearity, also avoids the inconvenient system singularities. The corresponding tracking error is shown to be globally asymptotically stable but only locally exponentially stable, while the controller maintains the four-rotor system motions inside a feasible region. Numerical simulations are presented to assesses the effectiveness of the proposed control strategy. © 2012 Taylor and Francis Group, LLC.

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