T-S Controllers For Photovoltaic-Grid Connected System Through DC-DC Boost Converter and Three Phase Inverter

Ce document présente deux contrôleurs flous TS en ligne pour contrôler l'extraction de puissance optimale et son transfert du système PV via deux convertisseurs statiques vers le réseau public. Le premier contrôleur est appliqué sur le convertisseur élévateur pour calculer, à chaque instant, le rapport cyclique permettant de suivre le point de puissance maximale du panneau sous les variations climatiques et d'atteindre un rendement élevé pour la récolte d'énergie solaire. Alors que le second ajuste les états de commutation des branches de l'onduleur triphasé à deux niveauxtransistors pour un transfert maximal de la puissance active produite par le panneau vers le réseau de distribution avec compensation de puissance réactive lors de l'établissement de la synchronisation.Après présentation de la structure du système de connexion au réseau et modélisation mathématique des convertisseurs côté PV et côté réseau, les contrôleurs flous TS sont détaillés. La synthèse de ces contrôleurs est basée sur la subdivision de l'espace d'états du système non linéaire à contrôler en un ensemble de sous-systèmes linéaires. Pour assurer le rejet des perturbations et garantir la stabilité du contrôleur flou,  Le critère et la fonction de stabilité quadratique de Lyapunov sont considérés. Les gains du contrôleur sont calculés en utilisant la solution d'inégalité de matrice linéaire (LMI). Les résultats de la simulation numérique sur l'environnement Matlab-Simulink montrent l'efficacité et les performances des contrôleurs proposés

Variabilité des descripteurs physiques, chimiques et phytoplanctonique dans des étangs d'alevinage (station de la Deroua, Béni-Mellal, Maroc)

Dans les étangs d'alevinage à la station de la Deroua, le phytoplancton est représenté par des populations se succédant dans le temps.Ces étangs montrent une similarité vis-à-vis de la variabilité des descripteurs de la qualité de l'eau. Les résultats statistiques montrent une variabilité des paramètres physiques et chimiques dépendant des interventions anthropiques.Les deux étangs B3 et B4 présentent des groupements phytoplanctoniques plus importants avec un développement de Cyanobactéries en fin du cycle d'alevinage lié à une forte biodisponibilité du phosphore dissous.In fry ponds at Deroua farm, the phytoplankton was represented by a temporal succession of taxa groups.This study showed a similar variability of physical and chemical parameters in fishponds. The statistical analysis proved a variability of these parameters depending of human interventions.At the end of fry period, the phosphorus concentration in B3 and B4 ponds allowed a development of Cyanobacteri

First occurrence of a Hymenosomatid crab <i>Elamena mathoei</i> (Desmarest, 1823) (Crustacea: Decapoda: Brachyura) in the Mediterranean Sea

Mediterranean fauna is undergoing drastic modifications as a result of anthropogenic activities and global warming. The most important of these is the colonization of the Mediterranean Sea by alien species, many of them entering through the Suez Canal. While many of them are still confined to the Levant Basin, several have extended their distribution westwards to Tunisian waters. The presence of the Indo-west Pacific hymenosomatid crab Elamena mathoei on a rocky shore at Sidi Daoud, Cape Bon Peninsula, Tunisia, is the first Mediterranean record of this species. It is a testimony to the changes in the patterns of invasion in the Mediterranean Sea

First occurrence of a Hymenosomatid crab Elamena mathoei (Desmarest, 1823) (Crustacea: Decapoda: Brachyura) in the Mediterranean Sea

Mediterranean fauna is undergoing drastic modifications as a result of anthropogenic activities and global warming. The most important of these is the colonization of the Mediterranean Sea by alien species, many of them entering through the Suez Canal. While many of them are still confined to the Levant Basin, several have extended their distribution westwards to Tunisian waters. The presence of the Indo-west Pacific hymenosomatid crab Elamena mathoei on a rocky shore at Sidi Daoud, Cape Bon Peninsula, Tunisia, is the first Mediterranean record of this species. It is a testimony to the changes in the patterns of invasion in the Mediterranean Sea

From random walk to multifractal random walk in zooplankton swimming behaviour

EDITORIAL OFFICE, TAIPEI, TAIWAN, 11

First record of the twobar sea bream Acanthopagrus bifasciatus (Teleostei: Sparidae) in the Mediterranean Sea

In September 2010, one specimen of the twobar seabream Acanthopagrus bifasciatus was recorded for the first time in the Mediterranean Sea, off the Islands of Zembra (Gulf of Tunisi: 37°07’03’’N; 10°48’35’’E). This species could have entered the Mediterranean via the Suez Canal or alternatively by unintentional human transport

Rendezvous of Two Robots with Constant Memory

We study the impact that persistent memory has on the classical rendezvous problem of two mobile computational entities, called robots, in the plane. It is well known that, without additional assumptions, rendezvous is impossible if the entities are oblivious (i.e., have no persistent memory) even if the system is semi-synchronous (SSynch). It has been recently shown that rendezvous is possible even if the system is asynchronous (ASynch) if each robot is endowed with O(1) bits of persistent memory, can transmit O(1) bits in each cycle, and can remember (i.e., can persistently store) the last received transmission. This setting is overly powerful. In this paper we weaken that setting in two different ways: (1) by maintaining the O(1) bits of persistent memory but removing the communication capabilities; and (2) by maintaining the O(1) transmission capability and the ability to remember the last received transmission, but removing the ability of an agent to remember its previous activities. We call the former setting finite-state (FState) and the latter finite-communication (FComm). Note that, even though its use is very different, in both settings, the amount of persistent memory of a robot is constant. We investigate the rendezvous problem in these two weaker settings. We model both settings as a system of robots endowed with visible lights: in FState, a robot can only see its own light, while in FComm a robot can only see the other robot's light. We prove, among other things, that finite-state robots can rendezvous in SSynch, and that finite-communication robots are able to rendezvous even in ASynch. All proofs are constructive: in each setting, we present a protocol that allows the two robots to rendezvous in finite time.Comment: 18 pages, 3 figure

The use of an economical medium for the production of alkaline serine proteases by Bacillus licheniformis NH1

The present study is concerned with the selection of new economical media based on agricultural and marine-processing by-products for the production of alkaline proteases by Bacillus licheniformis NH1. Powders from different fish species were prepared and then tested as growth media at a concentration of 10 g/l for proteases production by NH1 strain. Powder prepared from whole Sardinelle was found to be the best substrate for the production of the alkaline protease. The NH1 strain exhibited a slightlygreater protease production (2927 U/ml) in medium containing only whole Sardinelle powder than that obtained in control medium (2800 U/ml). Proteases were produced even when strain NH1 was cultivated in medium containing only powder prepared from combined heads and viscera Sardinelle (CHVSP), about 2117 U/ml. Protease production was also carried out in media containing hulled grain of wheat, a by-product of semolina factories, as carbon source. Maximum activity (2517 U/ml) was achieved when the strain was grown in medium containing hulled grain of wheat (10 g/l), casein peptone (2 g/l), K2HPO4 (0.5 g/l) and KH2PO4 (0.5 g/l). Moreover, protease production was considerably enhanced when thestrain was grown in medium containing both hulled grain of wheat and CHVSP as carbon and nitrogen sources, respectively, (4771 U/ml). The study shows that hulled grain of wheat and powders from fishery by-products could be utilized as bacterial substrates for the production of alkaline proteases by B. licheniformis NH1