5 research outputs found
Autonomous navigation for an unmanned aerial vehicle by the decomposition coordination method
No full textRendu-Osler-Weber Syndrome: A Rare Case Report and Literature Review
No full textRendu-Osler disease is a rare inherited vascular disorder. Through this article, the authors recall the digestive manifestations of this condition, which when associated with other clinical signs, are sufficiently characteristic to allow the gastroenterologist to suggest the diagnosis
A comparative study of the photocatalytic efficiency of metal oxide/hydroxyapatite nanocomposites in the degradation kinetic of ciprofloxacin in water
No full textThe photocatalytic efficiency of the metal oxide-hydroxyapatite photocatalysts prepared by soft chemistry using phosphate rock as calcium and phosphorus precursors has been investigated on the degradation kinetic of ciprofloxacin residues in water under UV-light (HPK125 W Lamp). The nature of metal oxide (TiO2, ZnO, Fe2O3), structure, surface area and pore-size distributions of the catalysts were analyzed by various techniques analyses. Association of nanoscale metal oxide with hydroxyapatite could enhance the sorption properties of the materials and confers them interesting photodegradation properties. The results of the kinetic study revealed that the activities of these photocatalysts were dependent on the oxide surface and the best activity was obtained with TiO2/hydroxyapatite catalyst, which had the largest surface area. The effects of various operational parameters were thoroughly considered in order to achieve highest photodegradation efficiency. A correlation between the nature of associated metal oxide, surface properties, the sorption behavior and the photodegradation capacity of these composites could be establishedd
Electrochemical and structural investigation of BixTey thin films electrodeposited on ITO substrate
No full textBismuth telluride films with various stoichiometries BixTey have been successfully elaborated by potentiostatic deposition on indium tin oxide (ITO) substrate from an acidic solution containing a mixture of different concentrations of Bi3+ and HTeO2+ ions. The electrochemical study using cyclic voltammetry and chronoamperometry shows that the electrodeposition of bismuth telluride is a quasi-reversible reaction controlled by the diffusion process and the composition of the reaction mixture controls the BixTey stoichiometry. It was found, from electrochemical and EDS analysis, that a mixture in stoichiometric proportions leads to the formation of bismuth tellurium Bi2Te3, an excess of telluryl ion HTeO2+ gives a product rich in tellurium Bi2-xTe3+x, but a high concentration of Bi3+ (compared to the stoichiometry) gives rise to the electrodeposition of a compound rich in bismuth Bi2+xTe3-x. The chronoamperometric analysis of current density-time transients using Scharifker-Hills model showed that the mechanism of deposition and growth of BixTey on ITO substrate takes place according to a progressive 3D nucleation for low Bi3+ concentration and 3D instantaneous nucleation for higher concentration. The morphology of the BixTey films is strongly depending to the electrolytes composition. The X-ray diffraction characterization shows that the crystalline structure of bismuth tellurium BixTey produced is of the rhombohedral type
Autonomous Navigation for an Unmanned Aerial Vehicle by the Decomposition Coordination Method
Get PDFThis paper introduces a new approach for solving the navigation problem of Unmanned Aerial Vehicles (UAV) by studying its rotational and translational dynamics and then solving the nonlinear model by the Decomposition Coordination method. The objective is to reach a destination goal by the mean of an autonomous computed optimal path calculated through optimal control sequence. Solving such complex systems often requires a great amount of computation. However, the approach considered herein is based on the Decomposition Coordination principle, which allows the nonlinearity to be treated at a local level, thus offering a low computing time. The stability of the method is discussed with sufficient conditions for convergence. A numerical application is given in consolidation the theoretical results
