Témoignage de Lucien Legrand, Entraîneur National de Basket-ball

Legrand Lucien. Témoignage de Lucien Legrand, Entraîneur National de Basket-ball . In: Les Cahiers de l'INSEP, n°16-17, 1996. Sélection et préparation terminale pour les championnats du monde et les Jeux olympiques. pp. 157-160

The Bible on culture. : Belonging or dissenting?

New Yorkxvii, 190 p.; 24 cm

Récupération et basket-ball : la préparation terminale du championnat d'Europe cadets, 1997

Legrand Lucien, Touzé Jean-Marc. Récupération et basket-ball : la préparation terminale du championnat d'Europe cadets, 1997. In: Les Cahiers de l'INSEP, n°27, 2000. Sport de haut niveau et récupération. pp. 231-238

Low Latency Demodulation for High-Frequency Atomic Force Microscopy Probes

International audienceOne prerequisite for high-speed imaging in dynamic-mode atomic force microscopy (AFM) is the fast demod-ulation of the probe signal. In this contribution, we present the amplitude and phase estimation method based on the acquisition of four points per oscillation, with the sampling frequency being phase-locked on the probe actuation. The method is implemented on a RedPitaya platform, with its clock being generated from the actuation signal of the probe. Experimental characterizations using square-modulated sine waves show that latency of 500 ns is achieved with a carrier frequency of 10 MHz, which is ten times faster compared with a state-of-the-art lock-in amplifier. A tracking bandwidth greater than 200 kHz is obtained experimentally. The method is eventually applied to a close-loop AFM scan realized using a 15-MHz AFM probe, showing its suitability for high-frequency oscillating probes. Index Terms-Amplitude and phase demodulation, atomic force microscopy (AFM), field-programmable gate array (FPGA) implementation

Characterization of Tensile Properties of <i>Cola lepidota</i> Fibers

Plant fibers are being increasingly explored for their use in engineering polymers and composites, and many works have described their properties, especially for flax and hemp fibers. Nevertheless, the availability of plant fibers varies according to the geographical location on the planet. This study presents the first work on the mechanical properties of a tropical fiber extracted from the bast of Cola lepidota (CL) plant. After a debarking step, CL fibers were extracted manually by wet-retting. The tensile properties are first identified experimentally at the fibers scale, and the analysis of the results shows the great influence of the cross-section parameters (diameter, intrinsic porosities) on these properties. Tensile properties of CL fibers are also predicted by the impregnated fiber bundle test (IFBT). At this scale of bundles, a hackling step, which reduces shives and contributes to the parallelization of the fibers within bundles, improves tensile properties predicted by IFBT. The comparison with the properties of plant fibers given in the literature shows that CL fibers have tensile properties in the same range as kenaf, flax or hemp fibers

Manufacture and Characterization of Cola Lépidota Reinforcements for Composite Applications

This study represents the first works on the manufacture of reinforcements for composite applications such as yarns and fabrics using a tropical fiber extracted from the bast of the Cola Lepidota (CL) plant. Different types of products were produced, including twisted and untwisted yarns and woven and quasi-unidirectional fabrics to manufacture composite samples. At each scale, experimental characterizations of textile and mechanical properties were carried out; these properties are compared to those given in the literature concerning natural fiber materials. The results show that the tenacity of twisted and untwisted CL yarns is higher than that of similar products based on flax fibers, which is an important result for the weaveability of these rovings. At the fabric scale, the quasi-unidirectional architecture reduces waviness and shows promising tensile properties compared to woven fabrics. On the scale of composites, these developments made it possible to achieve properties in tensile comparable, particularly in stiffness, to those achieved by composites based on natural fibers. The objectives of this paper are to highlight the advantages and drawbacks of different types of reinforcements, and to present the first characterization of the properties of products based on CL fibers