Cost effective use of liquid nitrogen in cryogenic wind tunnels

A method of reliquefying from 12 to 19% of the nitrogen exhaust gas from a cryogenic wind tunnel has been developed. Technical feasibility and cost effectiveness of the system depends on performance of an innovative positive displacement expander which requires scale model testing to confirm design studies. The existing cryogenic system at the 0.3-m transonic cryogenic tunnel has been surveyed and extensive upgrades proposed. Upgrades are generally cost effective and may be implemented immediately since they are based on established technology

Comparison of H alpha synoptic charts with the large-scale solar magnetic field as observed at Stanford

Two methods of observing the neutral line of the large-scale photospheric magnetic field are compared: (1) neutral line positions inferred from H alpha photographs and (2) observations of the photospheric magnetic field made with low spatial resolution (3 arc min.) and high sensitivity using the Stanford magnetograph. The comparison is found to be very favorable

Eyes on the enterprise: problematising the concept of a teaching-research nexus in UK higher education

Existing research into the relationship between teaching and research in higher education is mainly normative and atheoretical, resulting in assumptions of a close and beneficial connection between them. We problematise the idea of a nexus by undertaking a critical examination of the concept through the lens of educational ideologies to theorise the changes over time that shape the ways teaching and research are practised. Two hundred seven academic staff in the Humanities and Social Sciences were surveyed in 10 universities in England and Wales; the universities were identified as having strength in teaching, research, or in both. Along with analysis of interviews with senior managers at these universities, findings suggest that systemic forces which separate teaching and research are evident in institutional contexts with implications for the idea of a nexus. While the nexus may exist in theory, in practice, we argue that teaching and research can be pulled in different directions by institutional priorities. Furthermore, in institutions which adopt an enterprise ideology, there are signs of a nascent nexus emerging between research and innovation

The Kato square root problem on vector bundles with generalised bounded geometry

We consider smooth, complete Riemannian manifolds which are exponentially locally doubling. Under a uniform Ricci curvature bound and a uniform lower bound on injectivity radius, we prove a Kato square root estimate for certain coercive operators over the bundle of finite rank tensors. These results are obtained as a special case of similar estimates on smooth vector bundles satisfying a criterion which we call generalised bounded geometry. We prove this by establishing quadratic estimates for perturbations of Dirac type operators on such bundles under an appropriate set of assumptions.Comment: Slight technical modification of the notion of "GBG constant section" on page 7, and a few technical modifications to Proposition 8.4, 8.6, 8.