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The aim of this investigation was to evaluate the modification of physicochemical properties (viscosity and density) of four vegetable oils (grapeseed, sunflower, avocado, and olive) during ozonation, and to relate such variation with the ozonation kinetics, the ozonation degree, and the ozonation by-products distribution. During ozonation, the monitorization of the double bonds' decomposition and accumulation of ozonation by-products yields defined the relationship between the ozonation degree and the physicochemical properties of the ozonated oils. The ozonated oils were characterized by FT-IR and 1H NMR. The ozonation degree was determined by the measurement of the total unsaturation (TU); this method quantified the substrate reactive with ozone contained in oils. During the ozonation, the variation of viscosity, density, and ozonation by-products exhibited differences among the studied oils, which was effectively correlated to the corresponding ozonation degree. These were characterized by the observed reaction rate constants obtained by a parametric algorithm based on the application of a nonlinear least mean square method. [ABSTRACT FROM AUTHOR]

This manuscript deals with the problem of controlling a virtualized humanoid robot with 16 degrees of freedom (DOF). The aim of this study was to design an output feedback discontinuous controller which must resolve the sequence of articulation movements to walk over disjoint stepping objects placed in front of the humanoid robot. The suggested controller considers the state restrictions, via a nonstandard strong Lyapunov function, corresponding to the angular displacements and velocities at each articulation. This study implements an extended state terminal second order sliding mode controller with time dependent gains, to ensure the finite-time tracking trajectory of each articulation of the humanoid robot. The terminal sliding mode (TSM) is implemented in a virtual platform developed in a computer-aided design software. For comparison purposes, the controller was compared with a state feedback and a first order sliding mode algorithms. [ABSTRACT FROM AUTHOR]

In this study, the biohydrogen (bioH2) production of a microbial consortium was optimized by adjusting the type and configuration of two impellers, the mixing regimen and the mass transfer process (KLa coefficients). A continuous stirred-tank reactor (CSTR) system, with a nonstandard geometry, was characterized. Two different mixing configurations with either predominant axial (PB4 impeller) or radial pumping (Rushton impeller) were assessed and four different impeller configurations to produce bioH2. The best configuration for an adequate mixing time was determined by an ANOVA analysis. A response surface methodology was also used to fully elucidate the optimal configuration. When the PB4 impellers were placed in best configuration, c/Dt = 0.5, s/Di = 1, the maximum bioH2 productivity obtained was 440 mL L−1 hr−1, with a bioH2 molar yield of 1.8. The second best configuration obtained with the PB4 impellers presented a bioH2 productivity of 407.94 mL L−1 hr−1. The configurations based on Rushton impellers showed a lower bioH2 productivity and bioH2 molar yield of 177.065 mL L−1 hr−1 and 0.71, respectively. The experiments with axial impellers (PB4) showed the lowest KLa coefficient and the highest bioH2 production, suggesting that mixing is more important than KLa for the enhanced production of bioH2. [ABSTRACT FROM AUTHOR]

The aim of this article is to study thein vivoeffect of the ozonation degree of vegetal oils on two related clinical tests, such as inflammation and wound-healing in healthy and diabetic mice, respectively. Ozonated grape seed (GS) and sunflower (SF) oils were used for this purpose. The ozonation degree (from 0 to 44%) of oils was determined by the total unsaturation method (TU). This technique served to quantify the oxidizable substrate of oils and tissue’s lipids. For inflammation studies, an ear edema was induced by croton oil. The latter was treated with GS and SF oils with different ozonation degree, ozonated physiological solution and indomethacin, as reference. To evaluate the wound-healing effect, a circular section was surgically removed from the dorsal side of mice. The wound was treated with ozonated oils, Furacin® ointment (nitrofurazone 2%) and their combination. The TU of lipids (TUL) extracted from inflamed tissues was proposed to identify the biochemical changes in those tissues. The results showed in this study confirmed the effectiveness of ozonated oils for both, anti-inflammatory and wound-healing effects. The better anti-inflammatory effect was correlated with the increasing of the TUL in treated tissues. Furthermore, the better inflammation inhibition (INI) was obtained with oils partially ozonated. The GS and SF oils ozonated up to 24% and 22% reached an INI of 25% and 29%, respectively. The complete wound-healing of diabetic mice treated with ozonated oils was obtained during the same time reported for wound-healing of non-diabetic mice. Infection signs were not observed during treatment. Overall, the application of ozonated GS and SF oils with a low ozonation degree showed promising results, compared with the application of commercial drugs. [ABSTRACT FROM PUBLISHER]

This article describes the study of the treatment of tequila industry vinasses based on the sequential application of coagulation-flocculation and heterogeneous catalytic ozonation. Coagulation-flocculation treatment used biopolymers to reduce the nondissolved organic matter and to reduce the degree of color units in effluent. Among six different substances, chitosan was the most efficient biopolymer to remove the highest chemical organic demand (COD) concentration (84.0%). The response surface technique was used to obtain the best attainable operation conditions of coagulation-flocculation process. The initial organic matter concentration, the reaction period and biopolymer concentration were selected as the independent variables. Two levels of analysis were performed: optimally and sensibility. The best reaction conditions were 3.23 × 104mg L−1of initial COD, 125.4 mg L−1of chitosan concentration, and 60.0 min of reaction. Ozonation process was performed on the effluent of coagulation-flocculation treatment. A batch reaction with 30 mg L−1of ozone in gaseous phase and a flow of 0.1 L min−1was implemented. Nickel oxide (100 mg L−1) was used as the catalyst of the ozonation reaction. Twice larger COD concentration removal was obtained when the catalyst participated in the reaction compared to the so-called conventional ozonation (12.00% in conventional case vs 26.70% in catalyst presence). An ultraviolet-visible (UV-Vis) spectroscopy study was conducted to obtain a preliminary evaluation of organic compounds removal by effect of the sequential method proposed in this study. A significant total organics removal from the tequila industry wastewater (measured as the integral of UV-Vis spectrum) of 398.6 conditional units was obtained when the conventional ozonation was used after coagulation-flocculation, but that value was increased up to 1609.12 conditional units when the catalyst was inserted into the reaction. [ABSTRACT FROM PUBLISHER]

There are many examples in science and engineering which are reduced to a set of partial differential equations (PDEs) through a process of mathematical modelling. Nevertheless there exist many sources of uncertainties around the aforementioned mathematical representation. Moreover, to find exact solutions of those PDEs is not a trivial task especially if the PDE is described in two or more dimensions. It is well known that neural networks can approximate a large set of continuous functions defined on a compact set to an arbitrary accuracy. In this article, a strategy based on the differential neural network (DNN) for the non-parametric identification of a mathematical model described by a class of two-dimensional (2D) PDEs is proposed. The adaptive laws for weights ensure the ‘practical stability’ of the DNN-trajectories to the parabolic 2D-PDE states. To verify the qualitative behaviour of the suggested methodology, here a non-parametric modelling problem for a distributed parameter plant is analysed. [ABSTRACT FROM AUTHOR]

In this study the tracking problem for a class of non-linear uncertain systems is analyzed. The considered class of non-linear systems are restricted by those verifying the global Lipschitz condition on non-linearities making them linear-like. A new sliding mode neurocontroller is suggested to solve this problem. The controller desing includes the on-line state estimates construction and the corresponding tracking control based on sliding mode approach and the reconstructed dynamics generated by a special non-linear observer. A special sliding mode technique during the "off-line training" to estimate the right-hand side of the given dynamics in finite-time was applied. This procedure allows use of these estimates for the best (in LQ-sense) nominal weights selection in the neuro observer designed. A switching (sign) type term is incorporated in the observer structure to correct the current state estimates using just the on-line measurable output. This observer is supplied with a new learning procedure with switching structure. Two illustrative examples are presented: a benchmark problem related with a nominal linear system and a real chemical procedure dealing with the organic compounds elimination by ozone effect. [ABSTRACT FROM AUTHOR]