Biocomposites based on thermoplastic polymers and natural fibers have recently been used in wind turbine blades, to replace non-biodegradable materials. In addition, carbon nanofillers, including carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs), are being implemented to enhance the mechanical performance of composites. In this work, the Mori–Tanaka approach is used for homogenization of a polymer matrix reinforced by CNT and GNP nanofillers for the first homogenization, and then, for the second homogenization, the effective matrix was used with alfa and E-glass isotropic fibers. The objective is to study the influence of the volume fraction Vf and aspect ratio AR of nanofillers on the elastic properties of the composite. The inclusions are considered in a unidirectional and random orientation by using a computational method by Digimat-MF/FE and analytical approaches by Chamis, Hashin–Rosen and Halpin–Tsai. The results show that CNT- and GNP-reinforced nanocomposites have better performance than those without reinforcement. Additionally, by increasing the volume fraction and aspect ratio of nanofillers, Young’s modulus E increases and Poisson’s ratio ν decreases. In addition, the composites have enhanced mechanical characteristics in the longitudinal orientation for CNT- reinforced polymer and in the transversal orientation for GNP-reinforced polymer.

Absbaer Total, partial and differential cross sections for charge exchange collisions between B3+ and He have been determined in the 1 eV-10 keV energy range. The results are in excellent agreement with experiment and show lhal model poteutial calculations can be successfully adapted to the study of two-electron systems. The role of rotational coupling and the Srueckelberg oscillafions of the differential cmss sections are carefully examined.

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The future trends of wind turbine blade materials are mostly centered around utilizing lighter materials with improved life cycle and low cost. In modern wind turbine blade, using green composite or biocomposite is a sustainable solution, especially for small wind turbine blade with natural fiber and biodegradable polymer. In this work, four natural fibers (Alfa, Flax, Sisal and Hemp) are used with Polypropylene (PP) thermoplastic polymer. The objective is to evaluate the elastic muduli of composite by two methods; Analytical Mori Tanaka theory and numerical with Digimat MF. The results show a good validation between the two methods. The comparison of the mechanical behaviour of the transversely isotropic of natural fibers indicate that the hemp have a good performance with high Young and shear modulus regarding to their low density, which can offer an excellent candidate for the manufacturing of small wind turbine blades in rural and isolated areas.

The 3D printing technology used for small tidal and wind turbines has great potential to change and overcome certain weaknesses in traditional manufacturing techniques. In rural areas and isolated communities, small turbine systems could be locally fabricated and assembled by using additive manufacturing machines and also can be employed to decrease residential energy consumption. The objective of the paper is to study the thermomechanical performance of 3D printing of a small-scale tidal turbine blade and their process using Digimat-AM because more research efforts are needed in this area. In this work, the tidal turbine blade is printed by using the Selective Laser Sintering SLS method with Polyamide 12 (PA12) and Polyether ether ketone (PEEK) polymers reinforced by carbon beads (CB) and glass beads (GB). This research examines conceptual considerations of small tidal turbines including material properties and aerodynamic parameters. Once the finite element evaluation has been completed, the deflection, residual stresses, temperature distribution, and the deformed blade or warpage can be obtained. It is concluded that PA12-CB has warpage higher than PA12-GB by 3.78%, and PEEK-CB has warpage lower than PEEK-GB by 8.4%. Also, the warpage of PA12-CB is lower than PEEK-CB by 10.31%, and the warpage of PA12-GB is lower than PEEK-GB by 20.95%. Therefore, the lowest warpage is observed for PA12-GB. Finally, the results showed that 3D printing presents an excellent opportunity in the design and development of tidal energy systems in the future.

The production of electrical energy has always been a subject of debate to fight against climate change and preserve natural resources. Several countries, including Morocco, have proposed ambitious policies to develop renewable energy sources of production in the short and medium term. The major problem of renewable sources production is their intermittent nature. Using storage units, particularly PETS' and molten salt technologies, will increase the penetration rate of renewable energies. The balance between production and consumption will optimize production, and it represents an important aspect of smart grids. In this article, an electrical energy consumption prediction was developed for the period 2019-2025, and optimization of the renewable energies injected within the grid was made by introducing the algorithm used. The results show that the use of storage units will increase the rate of renewable energies integration to 47.189% of the total installed capacity.

Abstract. The potential energy curves and the coupling matrix elements of the 1Z:+ and 1H states involved in the collision of the B 3÷ (ls 2) multicharged ion on a He target have been calculated by means of an ab initio method with configuration interaction. The total and partial capture cross-sections have been determined, using a semiclassical method. The results are in good agreement with experiment, exhibiting a strong influence of rotational coupling even at low energies.