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Nano ferrite samples of type ZnCoFe Pr O , 0 ≤ x ≤ 0.2, were prepared by co-precipitation method for different concentration of Pr ions at a calcination temperature of 823 K. The samples were characterized using x-ray diffraction and transmission electron microscope (TEM), UV spectroscopy, FTIR, and electron paramagnetic resonance (EPR). The increase in concentration of Pr ions shows a significant change in the formed nano ferrite particles size, degree of aggregation, energy band gap, and lattice parameters. X-band (9.24 GHz) EPR spectra at room temperature showed a decrease in the g factor as the Pr content was increased. Furthermore, the variation of the Pr concentration in the samples led to different aggregation states, ranging from isolated nanoparticles with average crystal size of 28.5 to about 15 nm, as confirmed by x-ray diffraction and high-resolution transmission electron microscopy. [ABSTRACT FROM AUTHOR]

Cobalt zinc ferrite nanoparticles (CoZnFeO) (∼5-8 nm in size) added to CuTlBaCaCuO superconductor samples, 0.00 ≤ x≤ 0.20 wt. %, were prepared using a singlestep solid-state reaction technique. The temperature dependence of the real ( χ ) and imaginary ( χ ) components of the magnetic susceptibility (ACMS) was measured at various ac magnetic field amplitudes (3-16 Oe). The results were analyzed by using Bean critical state model to estimate the critical current density ( J ) It was found that J increases as x increases up to 0.08 and then it decreases with further increase in x. X- and Q-Band (9.3 and 33. GHz) electron paramagnetic resonance (EPR) spectra were measured in the temperature range from 300 to 10 K.The g values of Cu monomer were found to correspond to that of rhombic site symmetry with g = 2.21 ± 0.02, g = 2.10 ± 0.02, and g = 2.02 ± 0.02. [ABSTRACT FROM AUTHOR]

This study examined gender differences in the factors related to physical activity in 832 Taiwanese adolescents. Differences in psychosocial and cognitive correlates were noted by gender group. Taiwanese adolescent girls reported lower physical activity self-efficacy and less perceived benefits and more perceived barriers to being active than boys. Girls compared to boys reported significantly more positive social support, modeling, and norms from parents to be active but significantly less social support and norms from their peers. Structural equation modeling was used to test the direct and indirect paths of a model of proposed correlates and physical activity. The results indicated that peer influences had both direct and indirect paths to physical activity for both genders. Among all examined variables, perceived self-efficacy was the strongest correlate of physical activity for these adolescents. The findings of this study provide information relevant to designing physical activity interventions targeted to Taiwanese adolescents. [ABSTRACT FROM AUTHOR]