The distribution of solar wind speeds during solar minimum: calibration for numerical solar wind modeling constraints on the source of the slow solar wind

It took the solar polar passage of Ulysses in the early 1990s to establish the global structure of the solar wind speed during solar minimum. However, it remains unclear if the solar wind is composed of two distinct populations of solar wind from different sources (e.g., closed loops which open up to produce the slow solar wind) or if the fast and slow solar wind rely on the superradial expansion of the magnetic field to account for the observed solar wind speed variation. We investigate the solar wind in the inner corona using the Wang-Sheeley-Arge (WSA) coronal model incorporating a new empirical magnetic topology–velocity relationship calibrated for use at 0.1 AU. In this study the empirical solar wind speed relationship was determined by using Helios perihelion observations, along with results from Riley et al. (2003) and Schwadron et al. (2005) as constraints. The new relationship was tested by using it to drive the ENLIL 3-D MHD solar wind model and obtain solar wind parameters at Earth (1.0 AU) and Ulysses (1.4 AU). The improvements in speed, its variability, and the occurrence of high-speed enhancements provide confidence that the new velocity relationship better determines the solar wind speed in the outer corona (0.1 AU). An analysis of this improved velocity field within the WSA model suggests the existence of two distinct mechanisms of the solar wind generation, one for fast and one for slow solar wind, implying that a combination of present theories may be necessary to explain solar wind observations.

Virtual reality as a visualisation tool: benefits and constraints

The benefits and applications of virtual reality (VR) in the construction industry have been investigated for almost a decade. However, the practical implementation of VR in the construction industry has yet to reach maturity owing to technical constraints. The need for effective information management presents challenges: both transfer of building data to, and organisation of building information within, the virtual environment require consideration. This paper reviews the applications and benefits of VR in the built environment field and reports on a collaboration between Loughborough University and South Bank University to overcome constraints on the use of the overall VR model for whole lifecycle visualisation. The work at each research centre is concerned with an aspect of information management within VR applications for the built environment, and both data transfer and internal data organisation have been investigated. In this paper, similarities and differences between computer-aided design (CAD) and VR packages are first discussed. Three different approaches to the creation of VR models during the design stage are identified and described, with a view to providing sharing understanding across the interdiscipliary groups involved. The suitable organisation of building information within the virtual environment is then further investigated. This work focused on the visualisation of the degradation of a building, through its lifespan, with the view to provide a visual aid for developing an effective and economic project maintenance programme. Finally consideration is given to the potential of emerging standards to facilitate an integrated use of VR. The convergence towards similar data structures in VR and other construction packages may enable visualisation to be better utilised in the overall lifecycle model.

Ensuring operational compliance and ethical responsibility in the regulation of ART: the HFEA, past, present, and future

Under the Public Bodies Bill 2010, the HFEA, cornerstone in the regulation of assisted reproduction technologies (ART) for the last twenty years, is due to be abolished. This implies that there is no longer a need for a dedicated regulator for ART and that the existing roles of the Authority as both operational compliance monitor, and instance of ethical evaluation, may be absorbed by existing healthcare regulators. This article presents a timely analysis of these disparate functions of the HFEA, charting reforms adopted in 2008 and assessing the impact of the current proposals. Taking assisted conception treatment as the focus activity, it will be shown that the last few years have seen a concentration on the HFEA as a technical regulator based upon the principles of Better Regulation, with little analysis of how the ethical responsibility of the Authority fits into this framework. The current proposal to abolish the HFEA continues to fail to address this crucial question. Notwithstanding the fact that the scope of the Authority's ethical role may be questioned, its abolition requires that the Government consider what alternatives exists - or need to be put in place - to provide both responsive operational regulation and a forum for ethical reflection and decision-making in an area which continues to pose regulatory challenges