In this paper, the critical current density measured from the real part of ac-susceptibility is in agreement with that calculated from Bean’s formula at constant frequency ( f = 98 Hz) in the temperature range 30–38K for a pure MgB2 sample. The temperature dependence of the imaginary part of ac-susceptibility (00–T ) shows the shifts in absorption peaks towards the lower temperature when the applied field is increased. Scanning electron microscopy images confirmed the synthesis of a good sample and agglomerates with fine grains.

We present a complex fluorescence study of a series of gadolinium oxide polycrystalline powders singly, doubly and triply doped with trivalent rare earth ions (Er3+, Tb3+, and Dy3+), to explore a possibility of their use as materials for white light emitting diodes. The excitation and luminescence spectra along with the decay kinetics were measured in the temperature range from 6 to 300 K. The luminescence efficiency was studied within the visible spectral range, i.e. −400 nm to 750 nm under excitation by 355 nm third harmonic Nd:YAG laser pulses.

This paper reports on the metacognitive listening strategies used by second language successful learners when listening to a text in English. It is part of a larger study where 82 students were surveyed in regards to metacognitive listening strategies using the Metacognitive Awareness Listening Questionnaire (MALQ). Three successful listeners from among the 82 students volunteered to take part in the verbal reports (think-aloud protocols) in an attempt to uncover the metacognitive listening strategies this group of learners uses.