Past Industrial and Interdisciplinary Workshops

11 December 2009
11:30
to
13:00
Ellis, Reis and Zygalakis
Abstract
• “Two Problems Relating to Sand Dune Formation” by Andrew Ellis • “Interface Sharpening with a Lattice Boltzmann Equation” by Tim Reis • “A Dual Porosity Model for the Uptake of Nutrients by Root Hairs” by Kostas Zygalakis
  • Industrial and Interdisciplinary Workshops
11 December 2009
10:00
to
11:15
Abstract
Atomistic computer simulation models are constructed to study a range of materials in which the atoms appear in novel environments. Two key research areas are considered: • The Growth and Structure Inorganic Nanotubes. A range of materials have been observed to form nanotubular structures (inorganic nanotubes - INTs) analogous to those well known for carbon. These INTs, which may have unique low-dimensional morphologies not simply related to known bulk polymorphs, potentially offer unique mechanical and electronic properties. A useful synthetic pathway is to use carbon nanotubes as templates using molten salts. Atomistic simulation models, in which the atom interactions are treated utilizing relatively simple potential energy functions, are developed and applied to understand the INT formation and stability. INT morphologies are classified by reference to folding two dimensional sheets. The respective roles of thermodynamics and kinetics in determining INT morphology are outlined and the atomistic results used to develop an analytic model to predict INT diameters. • Ordering on Multiple Length-Scales in Network-forming Liquids. Intermediate-range order (IRO), in which systems exhibit structural ordering on length-scales beyond the nearest-neighbour (short-range), has been identified in a wide range of materials and is characterised by the appearance of the so-called first sharp diffraction peak (FSDP) at low scattering angles. The precise structural origin of such ordering remains contentious and a full understanding of the factors underlying this order is vital if such materials (many of which are technologically significant) are to be produced in a controlled manner. Simulation models, in which the ion-ion interactions are represented by relatively simple potential functions which incorporate (many-body) polarisation and which are parameterised by reference to well-directed electronic structure calculations, have been shown to reproduce such IRO and allow the precise structural origin of the IRO to be identified. Furthermore, the use of relatively simple (and hence computationally tractable) models allows for the study of the relatively long length- and time-scales required. The underlying structures are analysed with reference to both recent (neutron scattering) experimental results and high level electronic structure calculations. The role of key structural units (corner and edge sharing polyhedra) in determining the network topology is investigated in terms of the underlying dynamics and the relationship to the glass transition considered.
  • Industrial and Interdisciplinary Workshops
4 December 2009
11:45
to
13:00
Stacy Williams
Abstract
HSBC Currency Trading has collaborated with the Oxford Maths Institute for over six years and is now working with its third DPhil student. In this workshop, we will look at the some of the academic research which has directly benefited the trading operation.
  • Industrial and Interdisciplinary Workshops
27 November 2009
10:00
Dr Gareth Wakefield
Abstract
Thin films of low refractive index nanoparticles are being developed for use as anti-reflection coatings for solar cells and displays. Although these films are deposited as a single layer, the comparison between a simple theoretical model and the experimental data shows that the coating cannot be treated as a such, but rather as a layer with an unknown refractive index gradient. Approaches to modelling the reflectance from such coatings are sought. Such approaches would allow model refractive index gradients to be fitted to the experimental data and would allow better understanding of how the structure of the films develops during fabrication.
  • Industrial and Interdisciplinary Workshops
13 November 2009
10:00
to
13:00
Abstract
The aim is to explore whether we can extend the work of PM Woodward first published many years ago, to see if we can extract more information than we do to date from our radar returns. A particular interest is in the information available for target recognition, which requires going beyond Woodward's assumption that the target has no internal structure.
  • Industrial and Interdisciplinary Workshops
6 November 2009
11:45
to
13:00
Sylvain Deville
Abstract
Understanding the critical parameters controlling the stability of solidification interfaces in colloidal systems is a necessary step in many domains were the freezing of colloids is present, such as materials science or geophysics. What we understand so far of the solidification of colloidal suspensions is derived primarily from the analogies with dilute alloys systems, or the investigated behaviour of single particles in front of a moving interface and is still a subject of intense work. A more realistic, multi-particles model should account for the particles movement, the various possible interactions between the particles and the multiple interactions between the particles and the solid/liquid cellular interface. In order to bring new experimental observations, we choose to investigate the stability of a cellular interface during directional solidification of colloidal suspensions by using X-ray radiography and tomography. I will present recent experimental results of ice growth (ice lenses) and particle redistribution observations, their implications, and open the discussion regarding the limitations of the technique and the potential for further progress in the field using this approach.
  • Industrial and Interdisciplinary Workshops

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