University of Birmingham

Computer simulations have become essential tools to help understand, and even to predict, the results of chemistry experiments. Many fundamental processes require the quantum mechanical nature of molecules to be taken into account for a realistic simulation. At present, however, we are unable to treat correctly the dynamics of more than a few atoms using quantum mechanics. As a result, one has to simulate either a reduced model system exactly, or the full system using approximate methods such as classical molecular dynamics. A useful route to overcome the limitations is to treat part of a system using quantum mechanics, and part of the system using more approximate methods. The proposed research aims to develop a promising new mixed dynamics algorithm in which the all important, but theoretically difficult, interaction between the different parts of the system is treated rigorously.As a test of the method we propose to simulate experiments that scatter water molecules off the surface of a protein. The scattering process will be described using full quantum mechanics, while the protein environment will be described dynamically and explicitely, but more approximately. Results should give insights into the nature of solvation at the molecular level.

Current recommendations for the control of footrot in sheep include vaccination. Footrot is caused by the Gram-negative anaerobe Dichelobacter nodosus which is classified into ten serogroups; A-I and M based on genetic variation in the fimbriae gene which provides motility and adhesion. There is one commercially available and licensed vaccine for footrot in the UK, Footvax, containing nine serogroups. Antigenic competition means that as the number of vaccine serogroups increases, the efficacy of the vaccine reduces. Published peer-reviewed scientific literature has provided evidence that using fewer serogroups of D. nodosus results in longer lasting protection and less clinical disease in comparison to the commercial vaccine. In Australia, a recently adopted strategy is for farms wishing to vaccinate to submit foot swab samples for determination of the footrot serogroups present in their flock. Once established, vaccine is provided containing a single serogroup found in that flock. Up to two serogroup vaccines are used concurrently. The aim of the project is to establish if targeted serogroup vaccination is more efficacious than the commercially available vaccine in reducing footrot prevalence in English flocks. A more effective vaccination strategy would lead to reduced reliance on antibiotics for the treatment of footrot, and a positive outcome for sheep welfare and farm profitability. Within flock trials will be designed and conducted to investigate the efficacy of serogroup specific vaccination in flocks with two or more serogroups. Swab samples will be used to analyse changes in D.nodosus load and serogroup following vaccination with serogroup specific and commercial footrot vaccine. The impact of vaccination on flock lameness prevalence, productivity, antibiotic use and subsequent profitability will be analysed. The potential reduction in antibiotic use at a national level will be estimated.

This proposal focuses on the fundamental interaction between longitudinal & planform vorticity in open channel flow. Planform vorticity is a priori excluded from all Reynolds averaged Navier-Stokes (RANS) equation models, but is known to be present in most overbank flows . The Shiono & Knight method of analysis (SKM) is an analytic approach to modelling the influence of vortical structures, mimics 4 key dominant flow processes, avoids the use of 3-D turbulence models and applies at full scale.Despite the value of the SKM approach being confirmed by recent work at HR Wallingford, the original ancillary equations for F (vorticity linked) are known to be inadequate for certain types of non-prismatic floodplains and strongly meandering rivers. One promising approach is to use a two-layer SKM model, splitting vertically the depth-averaging process into two parts, above and below the bankfull stage. This allows a laterally sliced model to be placed on top of another sliced model, with horizontal inter-facial shear added. The lower F values in each slice then represent the streamwise secondary flows, and the upper ones mimic both secondary flows at floodplain/main channel boundaries and plan form vorticity. This produces a much simpler 2-D depth-averaged approach for these types of channel, with all the advantages of SKM, over more complex 3-D turbulence models (LES or RANS). Work is needed to explore this novel theoretical approach, and to assess whether it can be turned into practical spreadsheet tools for use by engineers modelling floods.

We have a large multi-disciplinary EPSRC research programme (2017-2021) which has started looking at multiscale two-phase solid-liquid flows in various flow systems (e.g. microchannels, pipes, stirred vessels). The work includes collaboration with the University of Surrey and Daresbury Laboratory, and there is possibility for industrial collaboration. We would like to link a PhD project to this EPSRC programme, thus, the student will benefit from working alongside and interacting with experienced postdoctoral research fellows. There is also possibility for industrial collaboration. The movement of solid-liquid suspensions in pipes and vessels of various scales is a generic complex problem. Industries dependent on solid-liquid flow are numerous including chemicals, consumer goods, food, pharmaceuticals, oil, mining, river engineering, construction, power generation, biotechnology and biomedical. This project will address some of the experimental challenges of the problem using advanced Lagrangian (positron emission particle tracking (PEPT) and Eulerian particle imaging velocimetry (PIV) and micro-PIV) flow imaging techniques to develop the missing physical understanding of the pertinent phenomena of solid-liquid flow in different flow systems across the scales (micro, meso, macro). The work will also address, as appropriate, theoretical aspects of the project in collaboration with the other partners, which may include numerical simulations (e.g. CFD) depending on the candidate's background and interests.

to develop innovative methods to measure and model real rail capacity and to validate and improve capacity simulations and simulators