Parallel 3D Simulation of a Fault Gouge using the Lattice Solid Model

Despite the insight gained from 2-D particle models, and given that the dynamics of crustal faults occur in 3-D space, the question remains, how do the 3-D fault gouge dynamics differ from those in 2-D? Traditionally, 2-D modeling has been preferred over 3-D simulations because of the computational cost of solving 3-D problems. However, modern high performance computing architectures, combined with a parallel implementation of the Lattice Solid Model (LSM), provide the opportunity to explore 3-D fault micro-mechanics and to advance understanding of effective constitutive relations of fault gouge layers. In this paper, macroscopic friction values from 2-D and 3-D LSM simulations, performed on an SGI Altix 3700 super-cluster, are compared. Two rectangular elastic blocks of bonded particles, with a rough fault plane and separated by a region of randomly sized non-bonded gouge particles, are sheared in opposite directions by normally-loaded driving plates. The results demonstrate that the gouge particles in the 3-D models undergo significant out-of-plane motion during shear. The 3-D models also exhibit a higher mean macroscopic friction than the 2-D models for varying values of interparticle friction. 2-D LSM gouge models have previously been shown to exhibit accelerating energy release in simulated earthquake cycles, supporting the Critical Point hypothesis. The 3-D models are shown to also display accelerating energy release, and good fits of power law time-to-failure functions to the cumulative energy release are obtained.

Charitable giving: A test of a revised Theory of Planned Behaviour model

Recent world events aside, downward trends in donating behaviour in Australia have increased the need for research into the factors that inhibit and encourage charitable giving. A revised Theory of Planned Behaviour (TPB) model was used to determine the influence of attitudes, norms (injunctive, descriptive, and moral norms), perceived behavioural control (PBC), and past behaviour (PB) on intentions to donate money to charities and community service organisations. Respondents (N=186) completed a questionnaire assessing the constructs of the revised TPB model. Four weeks later, self-reported donating behaviour was assessed (n=65). Results showed support for the revised TPB model. Attitudes, PBC, injunctive norms, moral norms, and PB all predicted donating intentions. Descriptive norms did not predict intentions. Intention was the only significant predictor of selfreported behaviour four weeks later, with neither PBC nor PB having a direct effect on behaviour. Theoretical and applied implications of the results are discussed.

'Nothing good ever came out of Japan': Race-mixing and the limits of diaspora

This paper argues that postcolonial notions of diaspora are premised on immigrant subjectivities and standpoints which do not fully apprehend the mixed-race / bi-racial experience and the local effect of cultural hybridity in Western settings. The paper was prompted by a recent conversation with Dee, the daughter of a Japanese warbride. As a child Dee recalled being told by her friend's mother that 'nothing good ever came out of Japan'. The significance of constant interpolations into 'Asianness' by statements such as these; by the 'where do you come from?' question and by more blatant discriminations are inadequately addressed by traditional and postcolonial notions of diaspora. 'Roots' and 'routes' imagery feature prominently in discussions of diaspora and hybridity which aim to decolonise culture and identity in deconstructive moves that highlight their flexible, multiple, contractedness. While it has been argued that even these conceptualisations are problematic because they privilege orders of explanation, theory and standpoint that are forced back into line with traditional notions of discrete 'races', cultures, ethnicities and identities, cultural studies and postcolonial theorists do not appear to find this contradiction overly troubling. Lodged in bodies that do not easily conflate to neat either/or cultures, politics and genetics, race-mixing also defies and yet return us to culture and biology. However, I argue that their refractions though the same tired old orders of racial, ethnic, cultural and national differentiation prevent us from disregarding the discursive effects of racism and racialisation.