James W. P. Campbell

Sustainability and Heritage Conservation: Assessment of Environmental Performance and Energy Management for Historic Churches

This paper presents the preliminary findings of research on the sustainability in the historic built environment, currently being undertaken at the department of architecture, the University of Cambridge. The research focuses on the environmental performance of historic churches, whose construction typology - high ceilings, massive un-insulated masonry walls, decorative finishes, etc. - provides particularly difficult environmental challenges. This paper investigates the current environmental conditions occurring in four case studies in Cambridge and appraises the efficiency of different representative types of heating systems and strategies currently being used to regulate the indoor environment in the selected cases. The study has employed monitoring of the internal conditions and energy meter readings during autumn 2010 to estimate the energy consumed in each case. This paper presents the results and findings, and the first steps towards developing a conceptual framework for performance assessment and decision – making for public heritage buildings.

Limit case analysis of the “stable indenter velocity” method for obtaining creep stress exponents from constant load indentation creep tests

This study concerns a commonly-used procedure for evaluating the steady state creep stress exponent, n

A Study of Western Influence on Chinese Building Tools in Chinese Treaty Ports in the Early 20th Century

n

St Paul’s Cathedral: Archaeology and History

, from indentation data. The procedure involves monitoring the indenter displacement history under constant load and making the assumption that, once its velocity has stabilised, the system is in a quasi-steady state, with stage II creep dominating the behaviour. The stress and strain fields under the indenter are represented by “equivalent stress” and “equivalent strain rate” values. The estimate of n

A Study of Western Influence on Timber Supply and Carpentry in South China in the Early 20th Century

n

Evaluation of the lemon and banana signs in one hundred thirty fetuses with open spina bifida

is then obtained as the gradient of a plot of the logarithm of the equivalent strain rate against the logarithm of the equivalent stress. Concerns have, however, been expressed about the reliability of this procedure, and indeed it has already been shown to be fundamentally flawed. In the present paper, it is demonstrated, using a very simple analysis, that, for a genuinely stable velocity, the procedure always leads to the same, constant value for n

Morbidity and mortality of incontinence surgery in elderly women: An analysis of Medicare data☆☆☆★

n

A critical assessment of the “stable indenter velocity” method for obtaining the creep stress exponent from indentation data

(either 1.0 or 0.5, depending on whether the tip shape is spherical or self-similar). This occurs irrespective of the value of the measured velocity, or indeed of any creep characteristic of the material. It is now clear that previously-measured values of n

Johnson-Cook parameter evaluation from ballistic impact data via iterative FEM modelling

n

Wren and the development of structural carpentry 1660–1710

, obtained using this procedure, have varied in a more or less random fashion, depending on the functional form chosen to represent the displacement–time history and the experimental variables (tip shape and size, penetration depth, etc.), with little or no sensitivity to the true value of n