Mustapha Mabrouki

Mechatronic modeling of a 750 kW fixed-speed wind energy conversion system using the Bond Graph Approach

In this paper, we would like to focus on modeling main parts of the wind turbines (blades, gearbox, tower, generator and pitching system) from a mechatronics viewpoint using the Bond-Graph Approach (BGA). Then, these parts are combined together in order to simulate the complete system. Moreover, the real dynamic behavior of the wind turbine is taken into account and with the new model; final load simulation is more realistic offering benefits and reliable system performance. This model can be used to develop control algorithms to reduce fatigue loads and enhance power production. Different simulations are carried-out in order to validate the proposed wind turbine model, using real data provided in the open literature (blade profile and gearbox parameters for a 750 kW wind turbine).

Effect of temperature and plumbing materials on biofilm formation by Legionella pneumophila serogroup 1 and 2-15

Abstract The purpose of our study was to investigate the biofilm formation by Legionella pneumophila serogroup1 and serogroup2-15 on plumbing materials mostly used in building water systems in Morocco. The effect of plumbing materials and temperature were examined. The Atomic Force Microscopy was used to evaluate the roughness and surface topography of the plumbing materials including galvanized steel, stainless steel, copper, Polyvinyl chloride, Polypropylene Random Copolymer and Cross-linked polyethylene. Galvanized steel surfaces supported higher numbers of bacterial cells than that the stainless steel and plastic materials at 37 than 20 and 45 °C. Non-viable counts could be obtained from the copper surfaces. L. pneumophila sg2-15 strains presented a higher ability to biofilm formation than L. pneumophila sg1. The biofilm formation was evaluated by Atomic Force Microscopy.

Adhesion of Legionella pneumophila on glass and plumbing materials commonly used in domestic water systems

ABSTRACT We aimed to investigate the adhesion of Legionella pneumophila serogroup1 and L. pneumophila serogroup2–15 on glass, galvanized steel, stainless steel, copper, Polyvinyl chloride(PVC), Cross-linked polyethylene(PEX-c) and Polypropylene Random Copolymer(PPR). The surface physicochemical properties of both bacterial cells and materials were estimated through contact angle measurements. The roughness and surface topography of the materials were evaluated by Atomic Force Microscopy. The two L. pneumophila serogroups and plumbing materials showed a hydrophobic character, while glass surface was hydrophilic. All strains were adhered to all materials with the exception of copper. The result showed that the adhesion of both L. pneumophila sg1 and sg2–15 was systematically expressed with high intensity on galvanized steel followed by PVC, PEX-c, PPR, stainless steel and the low intensity on glass. The extent of adhesion is in correlation with the surface roughness and acid–bases interactions, while hydrophobicity seems to have no effect in adhesion intensity.