85 resultados para space science
em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast
Resumo:
Worldwide, science education reform is aiming to promote 'scientific literacy' among young people. Typically, this is taken to include empowering them to engage critically with science in news media. This study explored the extent and nature of secondary science teachers' use of newspapers. It found that, though a great many use the resource, the majority do so incidentally and with the intention of showing the relevance of the subject rather than developing their students' criticality.
Resumo:
An investigation on the design of aperiodic FSS is presented. First, an accurate yet efficient method which allows the analysis of finite sized aperiodic FSS has been developed. Subsequently, an optimisation method is implemented which optimises all the FSS elements to obtain an FSS design with an aperiodic element layout. Preliminary designs of aperiodic FSS are presented and the numerical results are discussed.
Resumo:
In experiments at the high-power Z-facility at Sandia National Laboratory in Albuquerque, New Mexico, we have been able to produce a low density photoionized laboratory plasma of Fe mixed with NaF. The conditions in the experiment allow a meaningful comparison with X-ray emission from astrophysical sources. The charge state distributions of Fe, Na and F are determined in this plasma using high resolution X-ray spectroscopy. Independent measurements of the density and radiation flux indicate unprecedented values for the ionization parameter xi = 20-25 erg cm s(-1) under nearly steady-state conditions. First comparisons of the measured charge state distributions with X-ray photoionization models show reasonable agreement, although many questions remain.