Resolution of an ancient surface science anomaly: Work function change induced by N adsorption on W{100}

For many decades it has been assumed that an adsorbate centered above a metal surface and with a net negative charge should increase the work function of the surface. However, despite their electronegativity, N adatoms on W{100} cause a significant work function decrease. Here we present a resolution of this anomaly. Using density functional theory, we demonstrate that while the N atom carries a negative charge, of overriding importance is a reduction in the surface overspill electron density into the vacuum, when that charge is engaged in bonding to the adatom. This novel interpretation is fundamentally important in the general understanding of work function changes induced by atomic adsorbates.

Imaging the future: theatre and change within the child protection system

The use of social pedagogy as a paradigm for critically appraising developments within child and family social work has been largely neglected. This paper outlines the work of Augusto Boal and his adoption of social pedagogy as a method for empowering oppres-sed social groups in Brazil. It is argued that Boal’s approach can be adapted by using action research techniques to analyse and effect change in situations where child care professionals face daily contradictions in their attempts to both protect children and support families. To demonstrate its relevance to child care practice, a description is provided of how the approach was used with two groups of social work students – one undertaking qualifying training, the other post-qualifying training. The results of this application suggest a new theoretical framework for practice which aims to establish communicative consensus around the needs of children and a mutual appreciation of roles and responsibilities.

The historical geography of ancient Sicily: implications for genetics.

Malone, C.A.T. and S.K.F. Stoddart, . (co-authored).