3,101 research outputs found
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
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
Formal Contexts, Formal Concept Analysis, and Galois Connections
Formal concept analysis (FCA) is built on a special type of Galois
connections called polarities. We present new results in formal concept
analysis and in Galois connections by presenting new Galois connection results
and then applying these to formal concept analysis. We also approach FCA from
the perspective of collections of formal contexts. Usually, when doing FCA, a
formal context is fixed. We are interested in comparing formal contexts and
asking what criteria should be used when determining when one formal context is
better than another formal context. Interestingly, we address this issue by
studying sets of polarities.Comment: In Proceedings Festschrift for Dave Schmidt, arXiv:1309.455
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
Hydrodynamic forces on steady and oscillating porous particles
We derive new analytical results for the hydrodynamic force exerted on a
sinusoidally oscillating porous shell and a sphere of uniform density in the
Stokes limit. The coupling between the spherical particle and the solvent is
done using the Debye-Bueche-Brinkman (DBB) model, i.e. by a frictional force
proportional to the local velocity difference between the permeable particle
and the solvent. We compare our analytical results and existing dynamic
theories to Lattice-Boltzmann simulations of full Navier-Stokes equations for
the oscillating porous particle. We find our analytical results to agree with
simulations over a broad range of porosities and frequencies
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