RESUMEN
The objective of this study was to compare the effectiveness of both small-sided games (SSG) and short interval running-based high-intensity interval training (HIIT) programs over an 8-week period in fostering adaptations in aerobic capacity, change-of-direction abilities, and jumping performances of youth female soccer players. The study involved 48 female youth participants under the age of 19, competing at the regional level, who took part in a randomized controlled trial. Participants were assigned to either the SSG group, the HIIT group, or a control group, which involved regular in-field sessions. Assessments were conducted at baseline and after the 8-week training intervention, measuring aerobic capacity using the 30-15 intermittent fitness test (VIFT), change of direction (COD) using the 5-0-5 test, and jumping performance using the countermovement jump test (CMJ). Time 5 group analysis revealed significant interactions in CMJ (p = 0.005; ηp2= 0.213) and VIFT (p < 0.001; ηp2 = 0.433), although no significant interaction were found in COD deficit (p = 0.246; ηp2 = 0.060). Within-group analysis revealed that SSG significantly improved CMJ (p < 0.001), COD deficit (p < 0.001), and VIFT (p < 0.001). HIIT group also significantly improved CMJ (p = 0.029), COD deficit (p = 0.001), and VIFT (p < 0.001). As conclusion, the study revealed that SSG promoted significantly improvements in VIFT, CMJ and COD deficit, being significantly better than control group, while HIIT was only significantly better than control in VIFT. SSG revealed to be effective approach for favoring key physical attributes of female soccer players, being an interesting and recommended training approach to increase the ecology of the training practice, while favoring physical positive adaptations.
Asunto(s)
Adaptación Fisiológica , Rendimiento Atlético , Entrenamiento de Intervalos de Alta Intensidad , Fútbol , Humanos , Fútbol/fisiología , Femenino , Entrenamiento de Intervalos de Alta Intensidad/métodos , Adolescente , Rendimiento Atlético/fisiología , Prueba de Esfuerzo , Ejercicio Pliométrico/métodos , Carrera/fisiologíaRESUMEN
Ru-doped Co9S8 hollow porous polyhedrons (Ru-Co9S8 HPPs) derived from zeolitic-imidazolate-frameworks were synthesized through hydrothermal coprecipitation and thermal decomposition methods. The results indicate that Ru-Co9S8-500 HPPs possess a strong Ru-Co synergistic effect, large electrochemical surface area, and sufficient active sites, endowing them with excellent hydrogen evolution reaction performance.
RESUMEN
In this study, porous magnetic CoFe2O4 nanocrystals (NCs) were successfully synthesized by using bimetal-organic framework (MOF) as a precursor, and used as catalysts to activate peroxymonosulfate (PMS) for the removal of chloramphenicol (CAP) in the solution. The structure and physicochemical properties of CoFe2O4 NCs were thoroughly examined by a series of characterization techniques. The results revealed as-synthesized CoFe2O4 had a nanorod-shaped structure with high specific surface area (83.00 m2 g-1) and pore volume (0.31 cm3 g-1). Furthermore, the degradation efficiency (100%) and the removal of total organic carbon (68.09%) were achieved after 120 min with 0.1 g/L CoFe2O4 NCs, 2 mM PMS and 10 mg/L CAP at pH of 8.20. In addition, effects of catalyst dosage, PMS dosage, initial pH values, CAP concentration and co-existing anions as well as natural organic matters in the solution on the degradation efficiencies were studied and all the removal can be well fitted with pseudo-first-order kinetic model (R2 > 0.96). Sulfate radicals (SO4â¢-) and hydroxyl radicals (HOâ¢) were proved to be two main reactive species for CAP removal in CoFe2O4/PMS system based on quenching experiments. CAP was degraded by the main pathways of dichlorination, denitration, decarboxylation, hydroxylation, ring cleavage and chain cleavage on CoFe2O4/PMS system through high performance liquid chromatograph-mass spectrometry analysis. We believe that this study would be very meaningful to promote the applications of MOFs-derived catalysts on the SO4â¢- based advanced oxidation processes (SR-AOPs) for the environmental remediation.
Asunto(s)
Cloranfenicol , Nanopartículas , Fenómenos Magnéticos , Estructuras Metalorgánicas , PeróxidosRESUMEN
In the past few years, orbital angular momentum (OAM) has aroused great interest in the scientific communities, because it shows great potential for enhancing capacities of radio and optical communication systems. Here, we propose anisotropic metasurfaces to generate multiple OAM vortex beams at microwave frequencies. A phase compensation theory is presented, in order to determine the phase distributions on metasurfaces, This theory enables independent control of beam numbers, polarizations, orientations, and topological charges of OAM vortex beams, respectively. The metasurface is composed of anisotropic elements, whose reflection phases can be engineered separately in different polarization directions. The scheme is validated by both simulation and experimental results and shows great potential for the polarization division multiplexing in OAM communication systems.