Conception et contrôle des chaînes d'approvisionnement tenant compte des phénomèmes aléatoires

Ce projet porte sur la conception et le contrôle d'un réseau manufacturier fiable tenant compte des phénomènes aléatoires. Notre objectif est de trouver et implanter les bons modes de gestion afin d'améliorer la fiabilité du réseau manufacturier qui subit différentes perturbations, ce qui permet de changer la conception initiale du réseau et donner une configuration optimale. La résolution de ce problème nécessite l'utilisation d'une approche hybride qui combine la programmation linéaire mixte en nombres entiers avec la simulation par événements discrets. Une telle approche est utilisée pour déterminer, à l'aide du modèle d'optimisation, la configuration optimale du réseau ainsi que le plan de planification, le programme linéaire sera par la suite suivi par la simulation à événements discrets pour valider, en premier lieu, les résultats mathématiques et donner, en deuxième lieu, une configuration et une planification plus réalistes et fiables en considérant les aspects aléatoires du réseau manufacturier

Synthesis of Silver and Gold Nanoparticles from Rumex roseus Plant Extract and Their Application in Electrochemical Sensors

The room-temperature synthesis of silver (AgNPs) and gold (AuNPs) nanoparticles from aqueous solution of AgNO3 and HAuCl4 respectively, using Rumex roseus (RR) plant extract as a reducing agent, is reported here for the first time. The nanoparticles obtained were characterized by UV-Vis spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). The formation of nanoparticles with spherical-shaped morphology was verified by TEM and confirmed by UV-Vis spectroscopy through the analysis of Ag and Au plasmon resonance peak and DLS measurements. New electrochemical sensors have been developed by employing the synthesized Ag and Au nanoparticles as modifiers of glassy carbon electrode (GCE) and screen-printed carbon electrode (SPCE), respectively. The AgNPs-modified GCE was investigated for the electrochemical determination of hydrogen peroxide (H2O2). Further enhancement of electrochemical performances was obtained using a nanocomposite made of AgNPs and reduced graphene oxide (rGO)-modified GCE. The AuNPs-SPCE sensor was instead tested in the electrochemical sensing of riboflavin (RF). To our knowledge, this is the first paper reporting Rumex roseus plant extract as a source for the synthesis of metal nanoparticles and their use for developing simple, sensitive and reliable electrochemical sensors for H2O2 and RF

Evaluation of antioxidant, antinflammatory and antityrosinase potential of extracts from different aerial parts of Rhanterium suaveolens from Tunisia

AbstractThe genus Rhanterium (Asteraceae) is a widely distributed medicinal plant throughout western North Africa and some Rhanterium species are used in folk medicine. The aim of research was to investigate methanolic extracts from different parts (flowers, leaves, and stems) of Tunisian Rhanterium suaveolens as potential sources of bioactive products useful for healthy purposes. In particular, were analyzed the phenolic composition of these extracts and their antioxidant, anti‐inflammatory, and anti‐tyrosinase properties.The phytochemical analyses were performed using standard colorimetric procedures, HPLC‐DAD and HPLC‐DAD‐ESI‐MS. Then, several in vitro cell‐free assays have been used to estimate the antioxidant/free radical scavenging capability of the extracts. Moreover, in vitro, and in vivo anti‐melanogenesis activities of these extracts were tested, respectively, with the tyrosinase inhibition assay and the Zebrafish embryo model. Finally, the anti‐inflammatory potential of these extracts in an in vitro model of acute intestinal inflammation in differentiated Caco‐2 cells was evaluated.The R. suaveolens extracts under study appeared particularly rich in flavonols and hydroxycinnamic acids and all extracts appeared endowed with good antioxidant/free radical scavenging properties, being the flower extracts slightly more active than the others. Moreover, R. suaveolens flowers extract was able to inhibit in vitro tyrosinase activity and exhibited bleaching effects on the pigmentation of zebrafish embryos. Furthermore, all extracts showed good anti‐inflammatory activity in intestinal epithelial cells as demonstrated by the inhibition of TNF‐α‐induced gene expression of IL‐6 and IL‐8.R. suaveolens aerial parts may be considered as a potential source of whitening agents, as well as of agents for the treatment of disorders related to oxidative stress and inflammation