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Over the years `short-range order' (SRO), whereby the local atomic arrangement differs from that of a random distribution, has been used to explain physical phenomena such as thermodynamic discontinuities, increased strength, anomalous electrical resistivity and magnetic variations in a host of alloys. However, due mainly to experimental difficulties and the complexity of the calculations required for the analysis of diffuse scattering, such work has been largely abandoned and hence quantification and assessment of SRO is notably sparse in the literature. The recent development of reverse Monte-Carlo (RMC) methods for the analysis of total scattering data has opened a promising route for the assessment of a material's local environment and has already provided important insights into a host of complex chemical systems, including liquids, network glasses, nano-materials, functional oxides and metal organic frameworks. The work presented in this thesis focuses on the development of a new methodology for the analysis of local structural effects in metallic systems using total scattering, and the first systematic application to the study of alloys. The simulation of total scattering data from a range of model structures is used to show that the information content of total scattering functions, in particular the pair distribution function (PDF), is sufficiently high to allow the assessment of different types and degrees of short-range order. This is supported by a demonstration of how such orders can be quantified from large box models, produced by fitting total scattering data using the RMC algorithm, with the mathematical analyses outlined. This culminates in a proposed methodology for the analysis of SRO in alloys. Having developed this analytical methodology it is subsequently applied to a number of interesting alloy systems. To demonstrate the efficacy of this methodology it was first applied to the study of a sample of Cu$_{3}$Au - the classically cited case example of a system demonstrating SRO prior to an ordering transition. This experiment provides new insight into this well characterised transition, and also demonstrates the significance of data processing errors on the generation of artefacts in large box modelling. The technique is also applied to the study of the industrially important family of nickel superalloys, assessing ordering in the gamma-phase alloy Ni-Cr and the sublattice orderings occurring in L1$_{2}$ alloys. Next, the use of the technique for the analysis of local strains exhibited in a lattice is presented. A series of models is used to demonstrate how the PDF is expected to change under variations in local strain caused by increased concentration of atomic substitution and variation in atomic radii. This is subsequently used to study the characteristic high-entropy alloy (HEA) CrMnFeCoNi. Through analysis of the PDF, it is demonstrated that the level of local strain exhibited in this alloy is not significantly different from those of other related compositionally simpler alloys. This result is highly significant as it challenges one of the core principles of the field - that the lattices of HEAs are necessarily highly strained. Finally, the energetics of ordering reactions are briefly considered and used to justify some of the observed transformations presented in the earlier work. Together, the body of work in this thesis shows how the total scattering technique can be used to provide valuable insight into a host of interesting local phenomena occurring in alloy systems. It is hoped that this will open up a new field of study into these effects, and ultimately guide the creation of new alloys based on these structure-property relationships.

Over the course of the nineteenth century and early twentieth century, Wales experienced its most sustained and prononounced phase of demographic growth. Migration was a critical catalyst in this process, of which the most substantial contributors in terms of absolute volume were English migrants. By 1900, approximately 16% to 25% of the Welsh population was either English-born or the first-generation relations of English migrants. However, the significance of their presence in Welsh society during this period is inversely proportional to their presence in the historiography: there exists no major study devoted solely to the issue of English migration to Wales, while tangential academic discussion of the topic generally tends to focus on its negative aspects (primarily in the context of the decline of the Welsh language). This thesis will thus seek to address the aforementioned historiographical shortcomings, while endeavouring to present a more rounded analysis of the socio-cultural traits of English migrants in Wales as well as their role in shaping the complexion of contemporary public discourse. It will deploy both quantitative and qualitative methodologies to achive these objectives, making use of relevant data from both the 1891 and 1901 censuses, the abundance of material derived from contemporary newspapers, journals and other publications, and a limited range of personal accounts from English migrants themselves. The overarching aim is to contextualise the particular experiences of English migrants within the broader development of Wales' modern national identity.