El control de la alostasis en un mesociclo de alta intensidad mediante el cuestionario modificado de Ogilvie

El control de la alostasis se ha convertido en los últimos años en un proceder indispensable a la hora de evaluar el proceso del entrenamiento por parte de los entrenadores y de los asesores científicos de muchos deportes, no solo profesionales, sino también de clubes o asociaciones deportivas de carácter lúdico. El objetivo de este estudio fue validar el cuestionario modificado de Ogilvie. Muestra: deportistas de alto rendimiento (DAR) (n= 25). Edad media DAR (19,23). Para ello se ha utilizado una herramienta que evaluó la fatiga muscular (TMG) y otra que evaluó la fatiga del sistema nervioso central (Flicker Fusion). A los deportistas se les pasó el cuestionario modificado de Olgivie en la misma sesión que se les evaluó la capacidad contráctil de la musculatura por medio del TMG y el punto crítico de Fusión (CFF) con el sistema Flicker Fusion. El análisis de los resultados sugiere que el cuestionario modificado de Ogilvie es una herramienta válida para el control de la alostasis en periodos de alta intensidad de entrenamiento

Physico-Chemical and Electrochemical Properties of Nanoparticulate NiO/C Composites for High Performance Lithium and Sodium Ion Battery Anodes

Nanoparticulate NiO and NiO/C composites with different carbon proportions have been prepared for anode application in lithium and sodium ion batteries. Structural characterization demonstrated the presence of metallic Ni in the composites. Morphological study revealed that the NiO and Ni nanoparticles were well dispersed in the matrix of amorphous carbon. The electrochemical study showed that the lithium ion batteries (LIBs), containing composites with carbon, have promising electrochemical performances, delivering specific discharge capacities of 550 mAh/g after operating for 100 cycles at 1C. These excellent results could be explained by the homogeneity of particle size and structure, as well as the uniform distribution of NiO/Ni nanoparticles in the in situ generated amorphous carbon matrix. On the other hand, the sodium ion battery (NIB) with the NiO/C composite revealed a poor cycling stability. Post-mortem analyses revealed that this fact could be ascribed to the absence of a stable Solid Electrolyte Interface (SEI) or passivation layer upon cycling

Physico-Chemical and Electrochemical Properties of Nanoparticulate NiO/C Composites for High Performance Lithium and Sodium Ion Battery Anodes

Nanoparticulate NiO and NiO/C composites with different carbon proportions have been prepared for anode application in lithium and sodium ion batteries. Structural characterization demonstrated the presence of metallic Ni in the composites. Morphological study revealed that the NiO and Ni nanoparticles were well dispersed in the matrix of amorphous carbon. The electrochemical study showed that the lithium ion batteries (LIBs), containing composites with carbon, have promising electrochemical performances, delivering specific discharge capacities of 550 mAh/g after operating for 100 cycles at 1C. These excellent results could be explained by the homogeneity of particle size and structure, as well as the uniform distribution of NiO/Ni nanoparticles in the in situ generated amorphous carbon matrix. On the other hand, the sodium ion battery (NIB) with the NiO/C composite revealed a poor cycling stability. Post-mortem analyses revealed that this fact could be ascribed to the absence of a stable Solid Electrolyte Interface (SEI) or passivation layer upon cycling

Magnetic structures of the α-Li3Fe2(PO4)3−x(AsO4)x (x=1, 1.5, 2, 3) solid solution

Mössbauer spectroscopy and neutron diffraction studies have been carried out for the α-Li3Fe2(PO4)3−x(AsO4)x (x=1, 1.5, 2, 3) solid solution, potential candidate for the cathode material of the lithium secondary batteries. The crystal and magnetic structures of all these phases are based on the structural and magnetic model corresponding to the α-Li3Fe2(PO4)3 phosphate parent, but with some differences promoted by the arsenate substitution. The PO4 and AsO4 groups have a random distribution in the structure. In all compounds the coupling of the magnetic moments takes place in the (001) plane, but the value of the angle between the moments and the x direction decreases from 38.3° (α-Li3Fe2(AsO4)3) to 4.7° (α-Li3Fe2(PO4)2(AsO4)1). This rotation arises from the change in the tilt angle between the Fe(1)O6 and Fe(2)O6 crystallographically and magnetically independent octahedra in the structures, and affects the effectiveness of the magnetic exchange pathways. The ordering temperature TN decreases with the increase of phosphate amount in the compounds. The existence of a phenomenon of canting and the evolution of the ferrimagnetic behavior in this solid solution is also discussed