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Work is underway in numerous countries around the world to design a viable nuclear fusion power station. It is hoped that this technology may one day provide a large amount of the world’s baseline power requirements. There are still numerous problems to be overcome in this field. The processing and refinement of hydrogen isotopes from mixed isotope sources is one such issue. Palladium already plays a part in existing infrastructure for this purpose. Existing work about the exact nature of the isotopic differences in the palladium hydride (/deuteride / tritide) system contains much conflicting evidence. This work is a study on the properties of the two lighter hydrogen isotopes (protium and deuterium) dissolved in palladium at high concentrations to form the well-established beta phase. Direct measurements of the tracer diffusion of these isotopes have been made for two sample geometries using quasielastic neutron scattering on Osiris at ISIS (Harwell, UK) and IN5 at The Institut Laue Langevin (Grenoble, France). Separate sorption measurements are also reported for each isotope to allow accurate determination of diffusion coefficients. Diffusion coefficients are reported for octahedral - octahedral jump diffusion in the beta phase for both isotopes. These results are used to calculate a temperature for the ‘crossover point’ in the diffusion rate of these isotopes (~730 K). This work also presents several unexpected results from these experiments: - A second diffusive motion, that does not appear to match any previously described, is reported for all samples and instruments. While it has not been possible to fully characterise this motion, its properties are investigated and discussed. - A high degree of ordering amongst the deuterium is inferred in the beta phase deuteride at temperatures between 433 and 500 K with around 55% of the available palladium interstitials occupied. This phenomenon has not previously been reported above 150 K. - Evidence for similar ordering and a possible transition in the ordered structure are reported for the beta phase hydride at similar temperatures and pressures.

This thesis presents a mixed method study of urban Tuberculosis, with reference to both social and physical factors. The initial study reports the social context of Tuberculosis in Brent, London. 104 subjects participated in focus group discussions from community organisations. Knowledge, perception and barriers to Tuberculosis treatment were explored. Participants included refugee, homeless and immigrant groups. A thematic analysis revealed stigma, memory of home life, knowledge of disease and Tuberculosis as ‘divine punishment’ as significant social factors. The professional groups reported language, patient expectations and the fragmentation of services as barriers to successful treatment. A second study explored the relationship between sunlight exposure and Vitamin D status in Tuberculosis cases and contacts. UVR exposure was measured using Polysulphone film over 8 weeks in an urban setting. Median values for 25(OH)D in index cases were 23.5 nmol/l and 33.0 nmol/l in contacts cases, at the end of the study period. Sun exposure was not significantly related to 25(OH)D in index cases ( r=0.016, sig=0.961, p=0.05) and showed only a weak positive correlation in contacts ( r=0.233, sig=0.44, p=0.05). No seasonal variation was evident in either group. The requirement to wear a film badge prevented some subjects taking part as this was perceived to be stigmatising. This was an unexpected finding. Only 12 index cases and 13 contacts completed the study. Finally, ambient UVR levels were measured in London and these data compared well with measurements from a rural site, suggesting that the potential for sun exposure is similar in both rural and urban settings. The stigma of Tuberculosis hinders treatment success as well as engagement with clinical research. Language difficulties and fragmentation of services make access and treatment completion challenging and complex. The built environment and lifestyle factors may influence the opportunity to obtain sufficient sunlight for Vitamin D sufficiency in those with Tuberculosis. Whether lack of sunlight causes Vitamin D deficiency requires further study.