Quantitative and Qualitative Analysis by HPLC of Major Peganum harmala Alkaloids at Different Stages of Development

The analysis of major Peganum harmala alkaloids (harmaline, harmine, harmol and harmalol) has shown that the content of these secondary metabolites depends on the plant development stage. The qualitative and quantitative profile of major alkaloids change significantly between stems, leaves and roots. The roots and seeds are the richest and most diversified organs in these metabolites. The concentration of the major alkaloids in all organs increases during the first three weeks and stabilizes at a constant level during vegetative growth phase and then decline at the beginning of flowering. On the scale of the whole plant, major alkaloids concentration of P. harmala varies with the developmental stage of the plant between 21.16 and 26.96 mg/g and harmine remains the most abundant molecule. Optimum exploitation of these natural products from the P. harmala plant is possible if the harvest of plant material occurs during the vegetative growth phase and at the appropriate stage for the richest organ. Keywords: Peganum harmala, Plant growth, Alkaloids, Harmine, Harmaline, Harmol, Harmalo

Identification of Electromagnetic waves produced by a magnetic pulse generator

International audienceThe study of the electromagnetic waves generated by an electromagnetic pulse generator is compelling either for the safety of instrumental equipment but more important for human being health. This is a major step to do in order to examine and explore the impact of the intense electromagnetic pulse machine before integrating it into an industrial environment. The electromagnetic pulse generator is used in many industrial applications such as forming, crimping, and welding of dissimilar materials. It is based on an RLC circuit connected to a one-turn massive coil, where the current pulse discharged in the coil is experimentally measured using a Rogowski coil. In this paper, we discuss the electromagnetic field generated around this generator since it is a mandatory step in the process of the deformation of metal parts. To measure the electromagnetic waves generated by the massive coil, we used a dipole antenna located in different positions around the coil. Results given by this experimental setup gives new insights about the electromagnetic field and specify its intensity and frequency

New Ethylenediamine Crosslinked 2D-Cellulose Adsorbent for Nanoencapsulation Removal of Pb (II) and Cu (II) Heavy Metal Ions: Synthesis, Characterization Application, and RSM-Modeling

The main objective of the present work is to elaborate on a new eco-friendly and efficient adsorbent designated for aquatic micropollutants removal. However, the synthesis of the Ethylenediamine Crosslinked 2D-Cellulose green adsorbent was carried out successfully, by partial grafting of benzyl entities onto hydroxyl groups of HEC, and crosslinking with ethylenediamine ED. Further, the new ethylenediamine crosslinked 2D-Cellulose was used as a biosorbent for nanoencapsulation removal of copper and lead heavy metal ions from aqueous solutions. The proposal chemical structures of unmodified and modified materials were confirmed using FTIR, XRD, TGA, and SEM–EDX analysis. Furthermore, many parameters of the optimization for Pb (II) and Cu (II) in terms of removal efficiency including pH, adsorbent amount, and contact time were optimized by response surface methodology with a Box–Behnken design. Based on the desirability optimization with three factors, the maximal removal was 99.52% and 97.5% for Pb(II) and Cu(II), respectively and was obtained at pH = 5.94, 22.2 mg as the optimal adsorbent amount, and 21.53 min as contact time

Spectre raman et dynamique cristalline de la transition de phase cubique-quadratique dans PbTi03

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Real-Time Implementation of Sliding Mode Controller for Buck Power Converter using DSpace 1104

This paper deals an experimental validation of a nonlinear controller using a sliding mode control (SMC) with integral action for a dc-dc buck power converter. The main control objectives are: i) perfect regulation of inductor current with unknown load resistance variation, ii) and ensure the asymptotic stability of the closed-loop system. To this end, a SMC with integral action is elaborated. Using Matlab-Simulink software, numerical simulations are carried out to show the effectiveness of the proposed approach. Furthermore, using an experimental test bench, the real-time controller is developed based on the Dspace 1104 card in real time (RT). It was shown, using formal analysis, simulations and experiments, that the controller achieves all desired performances