743 research outputs found

    New Light on John Davy

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    John Davy (1790–1868), the only brother of Sir Humphry Davy (1778–1829), was an army doctor, serving overseas, in various posts, in Belgium, France, Ceylon, the Ionian Islands, Malta, and the West Indies. He was also a researcher, a writer in his own right, and the editor of his brother’s works. This study, drawing principally on three unpublished manuscript sources recovered during work on the Davy Letters Project, examines a crucial, formative period in John Davy’s life – the years 1808–1814 – and situates him in the cultures and networks, scientific and literary, of which he was part. It explores John Davy’s time working as an assistant at the Royal Institution (1808–1811), a period he spent in Edinburgh as a student (1811–1813), and his engagement there in a scientific dispute with John Murray (1778–1820) over the chemical composition of muriatic acid gas, and the time he spent in his native Cornwall in 1814, prior to his first medical posting with the military

    Making space for past futures: rural landscape temporalities in Roman Britain

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    In this paper, we seek to explore the ways in which landscapes become venues not only for manipulations of the past in a present, but also for shaping possible futures. Considerations of temporality and being in the landscape have been more strongly focussed on the past and social memory than the future, anticipation, and projectivity, but these are vital considerations if we are to preserve the possibility that past people imagined alternative futures. A fruitful archaeological context for an exploration of past futures can be found in the choices people made during the late Iron Age and Roman period in Britain, which has an increasingly rich and high-resolution material record for complex changes and continuities during a period of cultural interactions and imperial power dynamics. More specifically, recent research into the architectural and material practices evident on rural settlement sites and across landscapes forces us to challenge pre-conceptions about the reactive/reactionary culture of rural societies. Case-studies from Kent and the West Country will be deployed to develop the argument that in the materialising of time, the future has a very significant part to play

    Mathematical Modelling of Tyndall Star Initiation

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    The superheating that usually occurs when a solid is melted by volumetric heating can produce irregular solid-liquid interfaces. Such interfaces can be visualised in ice, where they are sometimes known as Tyndall stars. This paper describes some of the experimental observations of Tyndall stars and a mathematical model for the early stages of their evolution. The modelling is complicated by the strong crystalline anisotropy, which results in an anisotropic kinetic undercooling at the interface; it leads to an interesting class of free boundary problems that treat the melt region as infinitesimally thin

    A mathematical model of serious and minor criminal activity

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    Wellposedness of an elliptic-dispersive coupled system for MEMS

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    In this work, we study the local wellposedness of the solution to a nonlinear elliptic-dispersive coupled system which serves as a model for a Micro-Electro-Mechanical System (MEMS). A simple electrostatically actuated MEMS capacitor device consists of two parallel plates separated by a gas-filled thin gap. The nonlinear elliptic-dispersive coupled system modelling the device combines a linear elliptic equation for the gas pressure with a semilinear dispersive equation for the gap width. We show the local-in-time existence of strict solutions for the system, by combining elliptic regularity results for the elliptic equation, Lipschitz continuous dependence of its solution on that of the dispersive equation, and then local-in-time existence for a resulting abstract dispersive problem. Semigroup approaches are key to solve the abstract dispersive problem.Comment: 27 page
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