Non-linear dynamic system identification: A multi-model approach

We are concerned with models which are able to describe multiple-input multiple-output (MIMO) non-linear dynamic systems. These models are represented in the form of rules and are known as Tagaki-Sugeno models. An identification algorithm for these models based on input and output data is presented. Parameter estimation is based on the calculation of model sensitivity functions with respect to their parameters. Some aspects of structure identification are also tackled, i.e. determination of local model orders and number of rules.     

Characterisation of northwest Moroccan honeys by gas chromatographic–mass spectrometric analysis of their sugar components

Combined gas chromatography–mass spectrometry (GC–MS) was used to analyse the sugar composition of honeys from northwest Morocco. This technique allowed the identification and quantification of two monosaccharides, eight disaccharides and three trisaccharides. In addition, characterisation of the main unifloral honeys by principal component analysis (PCA) and stepwise discriminant analysis (SDA) was carried out. PCA showed that the cumulative variance was approximately 50%, and about 70% of the samples were correctly classified using SDA, with the best results being obtained for the honeydew honeys (100% correct). © 2001 Society of Chemical Industry     

Cobalt oxide polymorph growth on electrostatic self-assembled nanoparticle arrays for dually tunable nano-textures

We report on a method for surface nano-texturing on a plastic substrate. Nano-objects with a silica nanoparticle core and a textured cobalt oxide crown are created with selectable density on the plastic substrate. The resulting dual morphology is easily tuned over large areas, either by changing the parameters directing nanoparticle deposition through electrostatic self-arrangement for nano-object density control, or the parameter directing cobalt oxide deposition for shape control. The entire process takes place at room temperature, with no chemicals harmful to the plastic substrate. The ready modulation of the dual morphology is used to control the wettability properties of the plastic film, which is covered by nano-objects.     

Analyzing the nanoindentation response of carbon black filled elastomers

Carbon black (CB) filled elastomers are structurally complex materials that offer unique properties at different length scales. They have tremendous potential applications in a number of fields including the automotive and aerospace industries and for designing innovative smart materials such as artificial muscles but their applications remain limited primarily due to inadequate understanding of their unique mechanical properties. Here, using the Berkovich technique to probe the surface mechanical properties at different scales the nanoindentation response of a series of composites made by homogeneously dispersed CB nanoparticles inside a semicrystalline copolymer matrix has been explored. While the measured loading part of the force–displacement curves is well described by Meyer's empirical power relation, the inverted methodology (IM) approach to deal with the unloading part has been considered and its outcome has been compared with that obtained from the standard Oliver–Pharr's method. The results were consistent with the observed increase of hardness when the applied displacement decreases for all composite samples over a large range of CB volume fraction. Zhang and Xu's model is demonstrated to produce experimentally consistent explanation of this indentation size effect. X-ray photoelectron spectroscopy (XPS) spectra also show composition gradients with depth up to 100 nm. Furthermore, the effect of CB content, surface features, and length scale-dependent deformation on the hardness–displacement behavior have been considered. These findings highlight the possibility of attaining a diverse set of mechanical properties by a better understanding of the nanoindentation response of CB filled elastomers which can be useful for material selection and design improvements in a number of practical applications.     

Characterisation of avocado (Persea americana Mill) honeys by their physicochemical characteristics

The quality of 12 avocado (Persea americana Mill) honeys from Spain was evaluated. Eight common physicochemical parameters were analysed, namely water content, pH, acidity (free, lactonic and total), sugar content, ash content and electrical conductivity. In addition, the honey samples were analysed using inductively coupled plasma optical emission spectrometry (ICP‐OES), and six minerals were quantified for each honey, namely potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), phosphorus (P) and sulphur (S). Most samples showed proper maturity considering the medium water content (mean 17.7%). The total acidity (below 50 meq kg^?1 except for one sample) indicated absence of undesirable fermentation; also, the mean pH of around 4.77 is usual in this kind of honey. The values for ash content and electrical conductivity were high (0.77% and 798 µS cm^?1 respectively) and typical of dark honeys. K was the predominant mineral (accounting for 73% of the total minerals quantified), followed by Na (10%). Copyright © 2004 Society of Chemical Industry     

Experimental Investigation on Effectiveness of a Vertical Drain under Cyclic Loads

This study examines the effectiveness of a prefabricated vertical drain (PVD) installed in reconstituted soft clay, where a large cyclic triaxial device was used to simulate repeated loading representing a rail track environment. The experimental data demonstrate that PVD successfully prevents excessive buildup of pore water pressure during cyclic loading, and that dissipation continues to occur after the load is removed. The findings of this study have direct relevance to rail track environments, e.g., in coastal Australia, where PVD installation beneath rail tracks constructed on low-lying estuarine soils has been recently introduced.     

Catalytic Partial Oxidation of Methanol and Methyl Mercaptan: Studies on the Selectivity of TiO2 and CeO2 Supported V2O5 Catalysts

Catalyst samples based on vanadium, cerium and titanium oxides were prepared using sol–gel method and wet impregnation. Several analytical techniques were used to characterize catalysts. The best activity and selectivity in the partial oxidation of methanol and methyl mercaptan were observed for the catalyst sample with the composition of 3 % V₂O₅/Ti_0.1–Ce_0.9O₂.