This project will create de novo enzymes for efficient and selective conversion of CO2 into CO and commodity chemicals, building from a first generation de novo CO2 reductase enzymes developed in the PI lab. Characterization of these de novo enzymes will provide a detailed understanding of the active site features and catalytic mechanisms controlling CO2 reduction and transformation to underpin the design of future generations of catalysts. These ambitions will be achieved by employing state-of-the-art methods in computational enzyme design, structural biology, genetic code expansion, directed evolution and biophysical enzyme characterization.

This project will focus on the analysis and development of tungsten diamond composites for fusion applications Technical Context ITER divertor plasma facing components (PFCs) are engineered to withstand 10 MW m-2 of steady-state surface heating. For comparison, the value is approximately 1 MW m-2 for a spacecraft heat shield during re-entry, 10-80 MW m-2 for an arc welder, and 50-150 MW m-2 for a cryogenically cooled rocket engine nozzle. For the last 25 years, progress in fusion has largely relied on the use of fine grain graphite and carbon fiber composites in the high heat-flux regions, where the carbon technology was adapted from the fission and aerospace industries. More recently, the carbon surface has been enhanced with high performance tungsten thin films (10-200 microns) in order to increase erosion resistance. Over a similar timeframe, diamond from CVD has become readily available. A UKAEA led research programme from 2007-2010 included: (i) a 5 mm thick boron-doped plate prototype exposed to high heat-flux electron beam testing, and (ii) thin films exposed to plasma in several fusion devices. CVD diamond is of interest because diamond has many relevant properties that are often best-in-class compared to all other materials: -isotropic thermal conductivity 5 times higher than copper at room temperature, -very low thermal expansion, -the above combine to give diamond unparalleled thermal shock resistance, -sublimates instead of melting, -low chemical reactivity with hydrogen in a gas environment, -forms strong carbide chemical bonds with many metals, including tungsten, -high tensile strength, and -good resistance to neutron radiation damage. Objective The goal is to work on developing and analysing tungsten diamond composites. This will contribute to the development of a multi layered composite tungsten diamond material in order to: a) reduce chemical reactivity, b) increase the erosion resistance to physical sputtering, c) marginal improved ductility at elevated temperatures, and d) quasi-self-repairing, since the diamond erodes until a new tungsten layer if the surface film is lost. This project will work on developing tungsten diamond composites and potentially a multi-layer composite and test them under fusion relevant conditions. Experimental analysis techniques will be used to assess the quality of the novel material.

This PhD project is centred on developing capability for probing the performance of AGR fuel cladding subjected to applied strain and exposure to aqueous environment to support the UK Nuclear Decommissioning Authority (NDA) strategy for implementing extended wet/dry storage of spent advanced gas-cooled reactor (AGR) fuel. The overarching goal is to provide a new methodology and confidence in probing miniature AGR fuel cladding samples, that can be transferred to hot cell working conditions on irradiated ex-service material. The Workington site provides access to a Deben 5KN miniature tensile rig and the unique set-up to simulate handling materials under hot cell conditions essential for this work. A set of manual straining rigs developed at Manchester and a similar miniature Deben rig (NNL) may also be accessed. The rigs will be interfaced with a range of characterisation techniques (e.g. Raman), allowing experiments to be carried out simulating different fuel storage scenarios. This project provides: (i) new capability for in-situ straining, corrosion, and stress corrosion cracking (SCC) testing of AGR cladding, (ii) assess Raman spectroscopy as a potential tool for AGR fuel cladding inspection, (iii) provide transferable knowledge/skills critical for probing AGR cladding in a hot-cell set-up to meet NDA strategy. The following key milestones will be addressed in this project: (i) A bench-top optical imaging system will be interfaced with these rigs to observe the cladding surface during straining for carrying out image correlation techniques. This will provide information about the distribution of surface strain. (ii) Application of Raman spectroscopy will be explored to assess the presence of NbC/NbCN precipitates, and their behaviour during the application of strain, and passive film characteristics. The latter will include probing the cladding surface before/after surface corrosion for exposing and dissolving these precipitates. NbC have been implemented to play a key role in the cladding degradation process. (iii0 A in-situ electrochemical cell (developed in a parallel NDA funded project) will be used for in-situ (stress) corrosion tests under electrochemical control to mimic wet pond storage conditions. (iv) The effect of minimal data on data quality will be explored with statistical means.

Resonance fluorescence of semiconductor quantum dots is one of the most promising ways to produce single photons for future quantum technologies. The spectrum emitted from a resonantly driven quantum dot exhibits characteristics such as antibunching and a subnatural linewidth, which are desired in a single-photon source. However, recent research (experimental and theoretical) has revealed that these characteristics cannot be observed simultaneously. This is because filtering of the emitted spectrum can affect the photon statistics of the emitted light, e.g. weakening the antibunching effect. Therefore, an in-depth understanding of the effects of spectral filtering is essential to the further progress in development of quantum dot single-photon sources. This project will develop novel theoretical methods to study the impact of filtering on the optical properties of semi-conductor quantum emitters. In particular, we will study the impact that electron-phonon interactions have on the emitted spectrum of a semiconductor quantum dot and how spectral filtering alters the resulting optical properties. This project will combine novel techniques from open quantum systems theory based on the master equation formalism with the filter formalism, to study the optical first- and second-order coherence of a quantum emitter.

The brain's vasculature is highly specialised. It tightly regulates transfer of essential molecules and ions into the brain, constantly maintaining a carefully balanced extracellular milieu in which neurones and other brain cells can function properly. In many neurological diseases such as dementia, stroke and brain tumours, the brain's vasculature becomes dysfunctional, allowing molecules to enter the brain unimpeded, disrupting this tightly controlled neurochemical balance. The transfer rate of water into and out of the brain is a common factor affected by disease. The correct regulation of water movement between different compartments of the brain is important for several reasons: i) Even small changes in the distribution of water between cellular compartments can drastically affect the composition of extracellular fluid, and hence the ability of brain cells to function properly, ii) Effective clearance and circulation of water in the brain is essential for removal of waste products such as amyloid-B, a protein which accumulates in brain's of people with Alzheimer's disease. The importance of well-regulated water balance is becoming increasingly recognised. There is now a need to understand the biophysical factors that drive changes in vascular water exchange so that drugs can be developed to restore brain water homeostasis. Our lab has developed approaches to measure vascular water exchange using MRI and we have demonstrated these method can detect changes in water exchange associated with ageing, AD, and peripheral inflammation. We now wish to use these techniques to study how changes to vascular proteins such tight junctions and aquaporins impact brain water balance, and how these changes impact brain health. This project will involve the use of knock out mouse models to determine the impact of specific genes on vascular and perivascular water exchange, then investigate the impact of abnormal water transport/movement in mouse models of Alzheimer's disease.