Prediction of Polyphenol Fraction in Virgin Olive Oil Using Mid-Infrared Attenuated Total Reflectance Attenuated Total Reflectance Accessory–Mid-Infrared Coupled With Partial Least Squares Regression

This study focuses on the quantification of virgin olive oil phenolic compound while using mid-infrared spectroscopy with chemometrics. For that, 100 samples of virgin olive oils in phenolic compounds which varied between 1.04 and 10.33 g/L were picked up in Morocco’s regions and subjected to infrared analysis. The aim was to develop a calibration model for the prediction of phenolic compounds in olive oil by using Fourier transform-infrared spectroscopy. The spectral transmissions of all samples were obtained in the spectral range of 600–4000 cm^–1. The values obtained for correlation coefficient and root mean square errors of prediction were 0.99 and 0.11, respectively. These results showed the capability of the Fourier transform-infrared spectroscopy and the chemometric in developing accurate models to predict the phenolic compounds in virgin olive oil.     

A formal model for plastic human computer interfaces

The considerable and significant progress achieved in the design and development of new interaction devices between man and machine has enabled the emergence of various powerful and efficient input and/or output devices. Each of these new devices brings specific interaction modes.With the emergence of these devices, new interaction techniques and modes arise and new interaction capabilities are offered. New user interfaces need to be designed or former ones need to evolve. The design of so called plastic user interfaces contributes to handling such evolutions. The key requirement for the design of such a user interface is that the new obtained user interface shall be adapted to the application and have, at least, the same behavior as the previous (adapted) one. This paper proposes to address the problem of user interface evolution due to the introduction of new interaction devices and/or new interaction modes. More, precisely, we are interested by the study of the design process of a user interface resulting from the evolution of a former user interface due to the introduction of new devices and/or new interaction capabilities. We consider that interface behaviors are described by labelled transition systems and comparison between user interfaces is handled by an extended definition of the bi-simulation relationship to compare user interface behaviors when interaction modes are replaced by new ones.     

Effect of axial load and transverse reinforcements on the seismic performance of reinforced concrete columns

The aim of this research is to assess the seismic performance of reinforced concrete columns under different axial load and transverse reinforcement ratios. These two parameters are very important as for the ductility, strength, stiffness, and energy dissipation capacity for a given reinforced concrete column. Effects of variable axial load ratio and transverse reinforcement ratio on the seismic performance of reinforced concrete columns are thoroughly analyzed. The finite element computer program Seismo-Structure was used to perform the analysis of series of reinforced concrete columns tested by the second author and other researchers. In order to reflect the reality and grasp the actual behavior of the specimens, special attention was paid to select the models for concrete, confined concrete, and steel components. Good agreements were obtained between the experimental and the analytical results either for the lateral force-drift relationships or for the damage progress prediction at different stages of the loading.     

Static output‐feedback for Takagi–Sugeno systems with delays

A practical methodology to design controllers for Takagi–Sugeno discrete‐time systems with unknown delays is proposed, based on using Linear Matrix Inequalities. More precisely, the design of discrete‐time output‐feedback stabilizing controllers in the presence of bounded delays is solved, when values of the disturbance attenuation and decay‐rate are imposed. A numerical example is provided to illustrate the proposed approach. Copyright © 2010 John Wiley & Sons, Ltd.     

Photochromic films prepared by vacuum co-deposition of polymer and spiropyrans

Photochromic polymer thin films have been prepared by vacuum co-deposition of PTFE and several spirocompounds. Their photochromic properties were studied with the use of the spectral-kinetic method. A number of positive properties for application of these films were found.     

Development of a virtual Couette rheometer for aerated granular material

A novel rheometer to study the behavior of granular materials in an aerated bed of particles has been developed. The device, called the aerated bed virtual Couette rheometer, is shown to be able to measure the shear stresses in the quasi-static and in the intermediate flow regimes. To validate the instrument, a Newtonian fluid of known viscosity was first sheared. The device was then used for measuring the shear stress of nonaerated glass beads with three -3D printed cells of different sizes to validate the optimal radial position, r*, where both shear rate and shear stress are independent of the cell radius. The results for the nonaerated glass beads displayed Coulomb behavior. The same behavior was observed when the bed was aerated. These experiments also showed that for a fixed shear rate the shear stress decreases as the aeration velocity, U. increases.     

Electrooxidation of Diacetone -L-Sorbose (DAS) into Diacetone-2-Keto-L-Gulonic acid (DAG) at nickel electrodes

The oxidation of diacetone-L-sorbose (DAS) into diacetone-2-keto-L-gulonic acid (DAG) is a step in the synthesis of vitamin C. This oxidation was carried out electrochemically in a stirred cell with the redox couple Ni (OH)₂/β-NiOOH as an electrochemical mediator. The anode was made of a current collector (nickel foam or platinized-titanium) and of a suspension of Ni(OH)₂ in KOH aqueous media. The mediated electrooxidation of DAS was achieved by the Ni(OH)₂β-NiOOH couple in solution which was regenerated at the current collector. This process required a two-compartment reactor but afforded high yields of chemical conversion: we obtained 96% with a 48% faradaic yield. Previous works dealing with DAS electrooxidation to DAG on nickel anode are reviewed hereafter.     

Kharasch addition of tetrachloromethane to alkenes catalyzed by metal acetylacetonates

Various transition metal acetylacetonates have proven to be efficient catalytic systems for the Kharasch addition of tetrachloromethane to alkenes under mild conditions, providing 1:1 adducts in up to 87% yield, based on internal standard. The nature of metal, solvent, temperature, olefin/CCl₄ ratio and the presence of nucleophilic co-catalysts were tested to evaluate the scope and limitation of the reaction.