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Shaun Hendy

Publications and source records attributed to Shaun Hendy.

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Asymmetric Assembly of Lennard-Jones Janus Dimers

Self-assembly of Janus (or `patchy') particles is dependent on the precise interaction between neighbouring particles. Here, the orientations of two amphiphilic Janus spheres within a dimer in an explicit fluid are studied with high geometric resolution. Molecular dynamics simulations and first-principles energy calculations are used with hard- and soft-sphere Lennard-Jones potentials, and temperature and hydrophobicity are varied. The most probable centre-centre-pole angles are in the range 40° to 55°, with pole-to-pole alignment not observed due to orientational entropy. Angles near 90° are energetically unfavoured due to solvent exclusion, and we unexpectedly found that the relative azimuthal angle between the spheres is affected by solvent ordering.

cond-mat.soft

Analysing Scientific Collaborations of New Zealand Institutions using Scopus Bibliometric Data

Scientific collaborations are among the main enablers of development in small national science systems. Although analysing scientific collaborations is a well-established subject in scientometrics, evaluations of scientific collaborations within a country remain speculative with studies based on a limited number of fields or using data too inadequate to be representative of collaborations at a national level. This study represents a unique view on the collaborative aspect of scientific activities in New Zealand. We perform a quantitative study based on all Scopus publications in all subjects for more than 1500 New Zealand institutions over a period of 6 years to generate an extensive mapping of scientific collaboration at a national level. The comparative results reveal the level of collaboration between New Zealand institutions and business enterprises, government institutions, higher education providers, and private not for profit organisations in 2010-2015. Constructing a collaboration network of institutions, we observe a power-law distribution indicating that a small number of New Zealand institutions account for a large proportion of national collaborations. Network centrality concepts are deployed to identify the most central institutions of the country in terms of collaboration. We also provide comparative results on 15 universities and Crown research institutes based on 27 subject classifications.

cs.DL

Instabilities in Granular Flow

We consider the stability of a system of equations which are a singular perturbation of the incompressible rigid-plastic flow equations used to model granular flow. A linear stability analysis shows that solutions of these equations are unstable, in general, and that these instabilities may lead to ill-posedness. However, the analysis suggests that these equations are more regular, in a certain sense, than the unperturbed incompressible rigid-plastic flow equations. Numerical solutions are presented which illustrate the growth of instabilities and the development of shear-bands in the flows.

cond-mat.soft