3 documents found, page 1 of 1
Modeling the growth kinetics of anodic TiO2 nanotubes
A. Apolinário; L. Andrade; A. Mendes; P. Quitério; C. T. Sousa; J. Ventura; J. B. Sousa; J. P. AraújoThe fundamental understanding of the barrier layer (delta(b)) growth in TiO2 nanotubes (NTs) is here established and compared with the classical metal oxidation theory from Mott and Cabrera. The role of delta(b) in the anodization of TiO2 NTs under different applied potentials and times was analyzed using scanning transmission electron microscopy (STEM). Contrary to the well-known case of anodic aluminum oxide,...
The role of the Ti surface roughness in the self-ordering of TiO 2 nanotubes: A...
A. Apolinário; L. Andrade; A. M. Mendes; C. T. Sousa; J. Ventura; J. D. Costa; D. C. Leitão; J. M. Moreira; J. B. Sousa; J. P. AraújoHighly ordered TiO2 nanotubes (NTs) were synthesized by electrochemical anodization of Ti foils. We investigated the effect of the Ti surface roughness (applying different pre-treatments prior to the anodization) on the length, growth rate and degree of self-organization of the obtained NT arrays. The mechanisms related to the TiO2 NT formation and growth were correlated not only with the corresponding anodizat...
A set-valued framework for coordinated motion control of networked vehicles
J. B. Sousa; F. L. PereiraA problem of coordinated control for two networked vehicles is presented, formulated, and solved to illustrate a set-valued framework for the coordinated control of networked vehicles. First, an informal user specification for the coordinated operation of two vehicles is introduced. Second, a formal representation of the objects and relations of interest is presented, and the user requirements are mapped onto a...