A people in exile, on the Way of the Cross: ministry deployment and ongoing decline in the Church of Scotland

In his paper, developed from original work for the Presbytery of Edinburgh, David Denniston broaches the difficult but essential task of beginning to think theologically about the Church in our own immediate context. Though, in the past, there have been theologians who have reflected on the relative power and status of the Church in society – the work of Donald MacKinnon for example – more recently this has been a rather minor consideration for more dominant discourses. In this paper, however, Denniston explores the future of the Church as a following of the Way of the Cross.Publisher PD

Hydrodynamics of topological defects in nematic liquid crystals

We show that back-flow, the coupling between the order parameter and the velocity fields, has a significant effect on the motion of defects in nematic liquid crystals. In particular the defect speed can depend strongly on the topological strength in two dimensions and on the sense of rotation of the director about the core in three dimensions.Comment: 4 pages including two figure

Micelle fragmentation and wetting in confined flow

We use coarse-grained molecular-dynamics (MD) simulations to investigate the structural and dynamical properties of micelles under non-equilibrium Poiseuille flow in a nano-confined geometry. The effects of flow, confinement, and the wetting properties of die-channel walls on spherical sodium dodecyl sulfate (SDS) micelles are explored when the micelle is forced through a die-channel slightly smaller than its equilibrium size. Inside the channel, the micelle may fragment into smaller micelles. In addition to the flow rate, the wettability of the channel surfaces dictates whether the micelle fragments and determines the size of the daughter micelles: The overall behavior is determined by the subtle balance between hydrodynamic forces, micelle-wall interactions and self-assembly forces

Phase Ordering in Nematic Liquid Crystals

We study the kinetics of the nematic-isotropic transition in a two-dimensional liquid crystal by using a lattice Boltzmann scheme that couples the tensor order parameter and the flow consistently. Unlike in previous studies, we find the time dependences of the correlation function, energy density, and the number of topological defects obey dynamic scaling laws with growth exponents that, within the numerical uncertainties, agree with the value 1/2 expected from simple dimensional analysis. We find that these values are not altered by the hydrodynamic flow. In addition, by examining shallow quenches, we find that the presence of orientational disorder can inhibit amplitude ordering.Comment: 21 pages, 14 eps figures, revte

Modelling nematohydrodynamics in liquid crystal devices

We formulate a lattice Boltzmann algorithm which solves the hydrodynamic equations of motion for nematic liquid crystals. The applicability of the approach is demonstrated by presenting results for two liquid crystal devices where flow has an important role to play in the switching.Comment: 6 pages including 5 figure

Simulations of collision times in gravity driven granular flow

We use simulations to investigate collision time distributions as one approaches the static limit of steady-state flow of dry granular matter. The collision times fall in a power-law distribution with an exponent dictated by whether the grains are ordered or disordered. Remarkably, the exponents have almost no dependence on dimension. We are also able to resolve a disagreement between simulation and experiments on the exponent of the collision time power-law distribution.Comment: 7 pages, 5 figure