The effects of acceleration stress on human workload and manual control

The effects of +Gz stress on operator task performance and workload were assessed. Subjects were presented a two dimensional maze and were required to solve it as rapidly as possible (by moving a light dot through it via a trim switch on a control stick) while under G-stress at levels from +1 Gz to +6 Gz. The G-stress was provided by a human centrifuge. The effects of this stress were assessed by two techniques; (1) objective performance measures on the primary maze-solving task, and (2) subjective workload measures obtained using the subjective workload assessment technique (SWAT). It was found that while neither moderate (+3 Gz) nor high (+5 Gz and +6 Gz) levels of G-stress affected maze solving performance, the high G levels did increase significantly the subjective workload of the maze task

‘So people know I'm a Sikh’: Narratives of Sikh masculinities in contemporary Britain

This article examines British-born Sikh men's identification to Sikhism. In particular, it focuses on the appropriation and use of Sikh symbols amongst men who define themselves as Sikh. This article suggests that whilst there are multiple ways of ‘being’ a Sikh man in contemporary post-colonial Britain, and marking belonging to the Sikh faith, there is also a collectively understood idea of what an ‘ideal’ Sikh man should be. Drawing upon Connell and Messerschmidt's discussion of locally specific hegemonic masculinities (2005. “Hegemonic Masculinity: Rethinking the Concept.” Gender and Society 19 (6): 829–859), it is suggested that an ideal Sikh masculine identity is partly informed by a Khalsa discourse, which informs a particular performance of Sikh male identity, whilst also encouraging the surveillance of young men's activities both by themselves and by others. These Sikh masculinities are complex and multiple, rotating to reaffirm, challenge and redefine contextualised notions of hegemonic masculinity within the Sikh diaspora in post-colonial Britain. Such localised Sikh masculinities may both assert male privilege and reap patriarchal dividends (Connell, W. 1995. Masculinities. Cambridge: Polity Press), resulting in particular British Sikh hegemonic masculinities which seek to shape the performance of masculinity, yet in another context these very same performances of masculinity may also signify a more marginalised masculinity vis-à-vis other dominant hegemonic forms

Children's play space and safety management: rethinking the role of play equipment standards

The provision of stimulating and engaging play space for children and young people is increasingly recognized as an important societal goal, not the least because it provides the young with opportunities to develop and gain experience in experimenting with risk. Research in several disciplines now suggests that achievement of this goal has however been impeded in recent decades, and reasons commonly cited have included fear of injury and avoidance of litigation. International standards on play equipment have also been promulgated and justified in terms of securing young people’s “safety,” most usually narrowly defined as injury reduction. There appears to be a widespread presumption that measures aimed at injury prevention are necessarily beneficial overall for young people’s welfare. In this article, we subject European standards for play equipment and surfacing to scrutiny. In particular, we examine underlying motives, consistency of purpose, use of evidence, philosophical leanings, scope, practicalities of application, systems of management, and legal ramifications. From this, we identify a number of fundamental issues that suggest that as a consequence of compartmentalized thinking and misunderstandings, these standards have invaded areas of decision making beyond their legitimate territory. The consequence of this is that play provision is skewed away from what are properly play provision objectives. In such circumstances, local decision makers are often disempowered, and their ability to provide optimal play spaces thereby circumscribed

Progress in thin film GaAs solar cells

Solar cells using polycrystalline films of gallium arsenid

Damping of bulk excitations over an elongated BEC - the role of radial modes

We report the measurement of Beliaev damping of bulk excitations in cigar shaped Bose Einstein condensates of atomic vapor. By using post selection, excitation line shapes of the total population are compared with those of the undamped excitations. We find that the damping depends on the initial excitation energy of the decaying quasi particle, as well as on the excitation momentum. We model the condensate as an infinite cylinder and calculate the damping rates of the different radial modes. The derived damping rates are in good agreement with the experimentally measured ones. The damping rates strongly depend on the destructive interference between pathways for damping, due to the quantum many-body nature of both excitation and damping products.Comment: 5 pages, 4 figure

Robustness of Planar Fourier Capture Arrays to Colour Changes and Lost Pixels

Planar Fourier capture arrays (PFCAs) are optical sensors built entirely in standard microchip manufacturing flows. PFCAs are composed of ensembles of angle sensitive pixels (ASPs) that each report a single coefficient of the Fourier transform of the far-away scene. Here we characterize the performance of PFCAs under the following three non-optimal conditions. First, we show that PFCAs can operate while sensing light of a wavelength other than the design point. Second, if only a randomly-selected subset of 10% of the ASPs are functional, we can nonetheless reconstruct the entire far-away scene using compressed sensing. Third, if the wavelength of the imaged light is unknown, it can be inferred by demanding self-consistency of the outputs.Comment: 15 pages including cover page, 12 figures, associated with the 9th International Conference on Position Sensitive Detector

Avoiding a dystopian future for children's play

Describes the conflict between children's freedom to play and the quest for safety and makes recommendations for the future

Analytic Representation of The Dirac Equation

In this paper we construct an analytical separation (diagonalization) of the full (minimal coupling) Dirac equation into particle and antiparticle components. The diagonalization is analytic in that it is achieved without transforming the wave functions, as is done by the Foldy-Wouthuysen method, and reveals the nonlocal time behavior of the particle-antiparticle relationship. We interpret the zitterbewegung and the result that a velocity measurement (of a Dirac particle) at any instant in time is, as reflections of the fact that the Dirac equation makes a spatially extended particle appear as a point in the present by forcing it to oscillate between the past and future at speed c. From this we infer that, although the form of the Dirac equation serves to make space and time appear on an equal footing mathematically, it is clear that they are still not on an equal footing from a physical point of view. On the other hand, the Foldy-Wouthuysen transformation, which connects the Dirac and square root operator, is unitary. Reflection on these results suggests that a more refined notion (than that of unitary equivalence) may be required for physical systems